Abstract
This manual describes MySQL Connector/J, the JDBC implementation for communicating with MySQL servers.
Document generated on: 2012-06-21 (revision: 30882)
Table of Contents
This manual describes MySQL Connector/J, the JDBC implementation for communicating with MySQL servers.
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This section explains how to configure and develop Java applications with MySQL Connector/J, the JDBC driver that is integrated with MySQL.
Table of Contents
There are currently four versions of MySQL Connector/J available:
Connector/J 5.1 is the Type 4 pure Java JDBC driver, which
conforms to the JDBC 3.0 and JDBC 4.0 specifications. It
provides compatibility with all the functionality of MySQL,
including 4.1, 5.0, 5.1, 5.4 and 5.5. Connector/J 5.1 provides
ease of development features, including auto-registration with
the Driver Manager, standardized validity checks, categorized
SQLExceptions, support for the JDBC-4.0 XML processing, per
connection client information,
NCHAR,
NVARCHAR and
NCLOB types. This release also includes all
bug fixes up to and including Connector/J 5.0.6.
Connector/J 5.0 provides support for all the functionality offered by Connector/J 3.1 and includes distributed transaction (XA) support.
Connector/J 3.1 was designed for connectivity to MySQL 4.1 and MySQL 5.0 servers and provides support for all the functionality in MySQL 5.0 except distributed transaction (XA) support.
Connector/J 3.0 provides core functionality and was designed for connectivity to MySQL 3.x or MySQL 4.1 servers, although it provides basic compatibility with later versions of MySQL. Connector/J 3.0 does not support server-side prepared statements, and does not support any of the features in versions of MySQL later than 4.1.
The following table summarizes the Connector/J versions available:
| Connector/J version | Driver Type | JDBC version | MySQL Server version | Status |
|---|---|---|---|---|
| 5.1 | 4 | 3.0, 4.0 | 4.1, 5.0, 5.1, 5.4, 5.5 | Recommended version |
| 5.0 | 4 | 3.0 | 4.1, 5.0 | Released version |
| 3.1 | 4 | 3.0 | 4.1, 5.0 | Obsolete |
| 3.0 | 4 | 3.0 | 3.x, 4.1 | Obsolete |
The current recommended version for Connector/J is 5.1. This guide covers all four connector versions, with specific notes given where a setting applies to a specific option.
The following table summarizes Connector/J Java dependencies:
| Connector/J version | Java RTE required | JDK required (to build source code) |
|---|---|---|
| 5.1 | 1.5.x, 1.6.x | 1.6.x and 1.5.x |
| 5.0 | 1.3.x, 1.4.x, 1.5.x, 1.6.x | 1.4.2, 1.5.x, 1.6.x |
| 3.1 | 1.2.x, 1.3.x, 1.4.x, 1.5.x, 1.6.x | 1.4.2, 1.5.x, 1.6.x |
| 3.0 | 1.2.x, 1.3.x, 1.4.x, 1.5.x, 1.6.x | 1.4.2, 1.5.x, 1.6.x |
If you are building Connector/J from source code using the source distribution (see Section 3.4, “Installing from the Development Source Tree”), you must use JDK 1.4.2 or newer to compile the Connector package. For Connector/J 5.1, you must have both JDK-1.6.x and JDK-1.5.x installed to be able to build the source code.
Because of the implementation of
java.sql.Savepoint, Connector/J 3.1.0 and
newer will not run on a Java runtime older than 1.4 unless the
class verifier is turned off (by setting the
-Xverify:none option to the Java runtime). This
is because the class verifier will try to load the class
definition for java.sql.Savepoint even
though it is not accessed by the driver unless you actually use
savepoint functionality.
Caching functionality provided by Connector/J 3.1.0 or newer is
also not available on JVMs older than 1.4.x, as it relies on
java.util.LinkedHashMap which was first
available in JDK-1.4.0.
MySQL Connector/J does not support JDK-1.1.x or JDK-1.0.x.
Table of Contents
You can install the Connector/J package using either the binary or
source distribution. The binary distribution provides the easiest
method for installation; the source distribution lets you
customize your installation further. With either solution, you
manually add the Connector/J location to your Java
CLASSPATH.
If you are upgrading from a previous version, read the upgrade information in Section 3.3, “Upgrading from an Older Version” before continuing.
Connector/J is also available as part of the Maven project. For more information, and to download the Connector/J JAR files, see the Maven repository.
For the easiest method of installation, use the binary
distribution of the Connector/J package. The binary distribution
is available either as a tar/gzip or zip file. Extract it to a
suitable location, then optionally make the information about
the package available by changing your
CLASSPATH (see
Section 3.2, “Installing the Driver and Configuring the CLASSPATH”).
MySQL Connector/J is distributed as a .zip or
.tar.gz archive containing the sources, the
class files, and the JAR archive named
mysql-connector-java-.
version-bin.jar
Starting with Connector/J 3.1.9, the .class
files that constitute the JAR files are only included as part of
the driver JAR file.
Starting with Connector/J 3.1.8, the archive also includes a
debug build of the driver in a file named
mysql-connector-java-.
Do not use the debug build of the driver unless instructed to do
so when reporting a problem or a bug, as it is not designed to
be run in production environments, and will have adverse
performance impact when used. The debug binary also depends on
the Aspect/J runtime library, which is located in the
version-bin-g.jarsrc/lib/aspectjrt.jar file that comes with
the Connector/J distribution.
Use the appropriate graphical or command-line utility to extract the distribution (for example, WinZip for the .zip archive, and tar for the .tar.gz archive). Because there are potentially long file names in the distribution, we use the GNU tar archive format. Use GNU tar (or an application that understands the GNU tar archive format) to unpack the .tar.gz variant of the distribution.
Once you have extracted the distribution archive, you can
install the driver by placing
mysql-connector-java-in your classpath, either by adding the full path to
it to your version-bin.jar
CLASSPATH environment variable, or
by directly specifying it with the command line switch
-cp when starting the JVM.
To use the driver with the JDBC
DriverManager, use
com.mysql.jdbc.Driver as the class that
implements java.sql.Driver.
You can set the CLASSPATH environment
variable under UNIX, Linux or Mac OS X either locally for a user
within their .profile,
.login or other login file. You can also set
it globally by editing the global
/etc/profile file.
For example, add the Connector/J driver to your
CLASSPATH using one of the following forms,
depending on your command shell:
# Bourne-compatible shell (sh, ksh, bash, zsh): shell> export CLASSPATH=/path/mysql-connector-java-ver-bin.jar:$CLASSPATH # C shell (csh, tcsh): shell> setenv CLASSPATH /path/mysql-connector-java-ver-bin.jar:$CLASSPATH
Within Windows 2000, Windows XP, Windows Server 2003 and Windows Vista, you set the environment variable through the System Control Panel.
To use MySQL Connector/J with an application server such as
GlassFish, Tomcat or JBoss, read your vendor's documentation for
more information on how to configure third-party class
libraries, as most application servers ignore the
CLASSPATH environment variable. For
configuration examples for some J2EE application servers, see
Chapter 7, Understanding J2EE Connection Pooling
Chapter 8, Managing Load-Balanced Connections,
and
Chapter 9, Load Balancing Failover Policies.
However, the authoritative source for JDBC connection pool
configuration information for your particular application server
is the documentation for that application server.
If you are developing servlets or JSPs, and your application
server is J2EE-compliant, you can put the driver's
.jar file in the
WEB-INF/lib subdirectory of your webapp, as
this is a standard location for third party class libraries in
J2EE web applications.
You can also use the MysqlDataSource or
MysqlConnectionPoolDataSource classes in
the com.mysql.jdbc.jdbc2.optional package, if
your J2EE application server supports or requires them. Starting
with Connector/J 5.0.0, the
javax.sql.XADataSource interface is
implemented using the
com.mysql.jdbc.jdbc2.optional.MysqlXADataSource
class, which supports XA distributed transactions when used in
combination with MySQL server version 5.0.
The various MysqlDataSource classes
support the following parameters (through standard set
mutators):
user
password
serverName (see the previous section
about fail-over hosts)
databaseName
port
This section has information for users who are upgrading from one version of Connector/J to another, or to a new version of the MySQL server that supports a more recent level of JDBC. A newer version of Connector/J might include changes to support new features, improve existing functionality, or comply with new standards.
In Connector/J 5.0.x and earlier, the alias for a table in
a SELECT statement is
returned when accessing the result set metadata using
ResultSetMetaData.getColumnName().
This behavior however is not JDBC compliant, and in
Connector/J 5.1 this behavior was changed so that the
original table name, rather than the alias, is returned.
The JDBC-compliant behavior is designed to let API users
reconstruct the DML statement based on the metadata within
ResultSet and
ResultSetMetaData.
You can get the alias for a column in a result set by
calling
ResultSetMetaData.getColumnLabel().
To use the old noncompliant behavior with
ResultSetMetaData.getColumnName(),
use the useOldAliasMetadataBehavior
option and set the value to true.
In Connector/J 5.0.x, the default value of
useOldAliasMetadataBehavior was
true, but in Connector/J 5.1 this was
changed to a default value of false.
Using the UTF-8 Character Encoding -
Prior to MySQL server version 4.1, the UTF-8 character
encoding was not supported by the server, however the JDBC
driver could use it, allowing storage of multiple
character sets in latin1 tables on the
server.
Starting with MySQL-4.1, this functionality is deprecated. If you have applications that rely on this functionality, and can not upgrade them to use the official Unicode character support in MySQL server version 4.1 or newer, add the following property to your connection URL:
useOldUTF8Behavior=true
Server-side Prepared Statements - Connector/J 3.1 will automatically detect and use server-side prepared statements when they are available (MySQL server version 4.1.0 and newer). If your application encounters issues with server-side prepared statements, you can revert to the older client-side emulated prepared statement code that is still presently used for MySQL servers older than 4.1.0 with the following connection property:
useServerPrepStmts=false
Connector/J 3.1 is designed to be backward-compatible with
Connector/J 3.0 as much as possible. Major changes are
isolated to new functionality exposed in MySQL-4.1 and newer,
which includes Unicode character sets, server-side prepared
statements, SQLState codes returned in
error messages by the server and various performance
enhancements that can be enabled or disabled using
configuration properties.
Unicode Character Sets:
See the next section, as well as
Character Set Support, for information on this MySQL
feature. If you have something misconfigured, it will
usually show up as an error with a message similar to
Illegal mix of collations.
Server-side Prepared Statements: Connector/J 3.1 will automatically detect and use server-side prepared statements when they are available (MySQL server version 4.1.0 and newer).
Starting with version 3.1.7, the driver scans SQL you are
preparing using all variants of
Connection.prepareStatement() to
determine if it is a supported type of statement to
prepare on the server side, and if it is not supported by
the server, it instead prepares it as a client-side
emulated prepared statement. You can disable this feature
by passing
emulateUnsupportedPstmts=false in your
JDBC URL.
If your application encounters issues with server-side
prepared statements, you can revert to the older
client-side emulated prepared statement code that is still
presently used for MySQL servers older than 4.1.0 with the
connection property
useServerPrepStmts=false.
Datetimes with all-zero
components (0000-00-00 ...): These
values cannot be represented reliably in Java. Connector/J
3.0.x always converted them to NULL
when being read from a ResultSet.
Connector/J 3.1 throws an exception by default when these
values are encountered, as this is the most correct
behavior according to the JDBC and SQL standards. This
behavior can be modified using the
zeroDateTimeBehavior configuration
property. The permissible values are:
exception (the default), which
throws an SQLException with an SQLState of
S1009.
convertToNull, which returns
NULL instead of the date.
round, which rounds the date to the
nearest closest value which is
0001-01-01.
Starting with Connector/J 3.1.7,
ResultSet.getString() can be decoupled
from this behavior using
noDatetimeStringSync=true (the default
value is false) so that you can
retrieve the unaltered all-zero value as a String. Note
that this also precludes using any time zone conversions,
therefore the driver will not allow you to enable
noDatetimeStringSync and
useTimezone at the same time.
New SQLState Codes:
Connector/J 3.1 uses SQL:1999 SQLState codes returned by
the MySQL server (if supported), which are different from
the legacy X/Open state codes that Connector/J 3.0 uses.
If connected to a MySQL server older than MySQL-4.1.0 (the
oldest version to return SQLStates as part of the error
code), the driver will use a built-in mapping. You can
revert to the old mapping by using the configuration
property useSqlStateCodes=false.
ResultSet.getString():
Calling ResultSet.getString() on a
BLOB column will now return
the address of the byte[] array that
represents it, instead of a String
representation of the BLOB.
BLOB values have no
character set, so they cannot be converted to
java.lang.Strings without data loss or
corruption.
To store strings in MySQL with LOB behavior, use one of
the TEXT types, which the
driver will treat as a java.sql.Clob.
Debug builds: Starting
with Connector/J 3.1.8 a debug build of the driver in a
file named
mysql-connector-java-
is shipped alongside the normal binary jar file that is
named
version-bin-g.jarmysql-connector-java-.
version-bin.jar
Starting with Connector/J 3.1.9, we do not ship the
.class files unbundled, they are only
available in the JAR archives that ship with the driver.
Do not use the debug build of the driver unless instructed
to do so when reporting a problem or bug, as it is not
designed to be run in production environments, and will
have adverse performance impact when used. The debug
binary also depends on the Aspect/J runtime library, which
is located in the
src/lib/aspectjrt.jar file that comes
with the Connector/J distribution.
Read this section only if you are interested in helping us test our new code. To just get MySQL Connector/J up and running on your system, use a standard binary release distribution.
To install MySQL Connector/J from the development source tree, make sure that you have the following prerequisites:
A Bazaar client, to check out the sources from our Launchpad repository (available from http://bazaar-vcs.org/).
Apache Ant version 1.7 or newer (available from http://ant.apache.org/).
JDK 1.4.2 or later. Although MySQL Connector/J can be be
used with older JDKs, compiling it from source requires at
least JDK 1.4.2. To build Connector/J 5.1 requires JDK 1.6.x
and an older JDK such as JDK 1.5.x;
point your JAVA_HOME environment variable
at the older installation.
To check out and compile a specific branch of MySQL Connector/J, follow these steps:
Check out the latest code from the branch that you want with one of the following commands.
The source code repository for MySQL Connector/J is located on Launchpad at https://code.launchpad.net/connectorj. To check out the latest development branch, use:
shell> bzr branch lp:connectorji
This creates a connectorj subdirectory
in the current directory that contains the latest sources
for the requested branch.
To check out the latest 5.1 code, use:
shell> bzr branch lp:connectorj/5.1
This creates a 5.1 subdirectory in the
current directory containing the latest 5.1 code.
To build Connector/J 5.1, make sure that you have both JDK
1.6.x installed and an older JDK such as JDK 1.5.x. This is
because Connector/J supports both JDBC 3.0 (which was prior
to JDK 1.6.x) and JDBC 4.0. Set your
JAVA_HOME environment variable to the
path of the older JDK installation.
Change your current working directory to either the
connectorj or 5.1
directory, depending on which branch you intend to build.
To build Connector/J 5.1, edit the
build.xml to reflect the location of
your JDK 1.6.x installation. The lines to change are:
<property name="com.mysql.jdbc.java6.javac" value="C:\jvms\jdk1.6.0\bin\javac.exe" />
<property name="com.mysql.jdbc.java6.rtjar" value="C:\jvms\jdk1.6.0\jre\lib\rt.jar" />
Alternatively, you can set the value of these property names
through the Ant -D option.
Issue the following command to compile the driver and create
a .jar file suitable for installation:
shell> ant dist
This creates a build directory in the
current directory, where all build output will go. A
directory is created in the build
directory that includes the version number of the sources
you are building from. This directory contains the sources,
compiled .class files, and a
.jar file suitable for deployment. For
other possible targets, including ones that will create a
fully packaged distribution, issue the following command:
shell> ant -projecthelp
A newly created .jar file containing
the JDBC driver will be placed in the directory
build/mysql-connector-java-.
version
Install the newly created JDBC driver as you would a binary
.jar file that you download from MySQL,
by following the instructions in
Section 3.2, “Installing the Driver and Configuring the CLASSPATH”.
A package containing both the binary and source code for Connector/J 5.1 can also be found at the following location: Connector/J 5.1 Download
Examples of using Connector/J are located throughout this document. This section provides a summary and links to these examples.
Example 6.1, “Connector/J: Obtaining a connection from the
DriverManager”
Example 6.2, “Connector/J: Using java.sql.Statement to execute a
SELECT query”
Example 6.6, “Connector/J: Setting CallableStatement input
parameters”
Example 6.7, “Connector/J: Retrieving results and output parameter values”
Example 6.9, “Connector/J: Retrieving AUTO_INCREMENT column values
using SELECT LAST_INSERT_ID()”
Example 6.10, “Connector/J: Retrieving AUTO_INCREMENT column values
in Updatable ResultSets”
Example 7.1, “Connector/J: Using a connection pool with a J2EE application server”
Example 15.1, “Connector/J: Example of transaction with retry logic”
Table of Contents
This section of the manual contains reference material for MySQL Connector/J.
The name of the class that implements
java.sql.Driver in MySQL Connector/J is
com.mysql.jdbc.Driver. The
org.gjt.mm.mysql.Driver class name is also
usable for backward compatibility with MM.MySQL, the predecessor
of Connector/J. Use this class name when registering the driver,
or when otherwise configuring software to use MySQL Connector/J.
The JDBC URL format for MySQL Connector/J is as follows, with items in square brackets ([, ]) being optional:
jdbc:mysql://[host][,failoverhost...][:port]/[database] » [?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]...
If the host name is not specified, it defaults to
127.0.0.1. If the port is not specified, it
defaults to 3306, the default port number for
MySQL servers.
jdbc:mysql://[host:port],[host:port].../[database] » [?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]...
Here is a sample connection URL:
jdbc:mysql://localhost:3306/sakila?profileSQL=true
For IPv6 connections, use this alternative syntax to specify
hosts in the URL,
address=(.
Supported keys are:
key=value)
(protocol=tcp), or
(protocol=pipe) for named pipes on
Windows.
(path=
for named pipes.
path_to_pipe)
(host=
for TCP connections.
hostname)
(port=
for TCP connections.
port_number)
For example:
jdbc:mysql://address=(protocol=tcp)(host=localhost)(port=3306)(user=test)/db
Any other parameters are treated as host-specific properties that follow the conventions of the JDBC URL properties. This now allows per-host overrides of any configuration property for multi-host connections (that is, when using failover, load balancing, or replication). Limit the overrides to user, password, network timeouts and statement and metadata cache sizes; the results of other per-host overrides are not defined.
If the database is not specified, the connection is made with no
default database. In this case, either call the
setCatalog() method on the Connection
instance, or fully specify table names using the database name
(that is, SELECT
) in your SQL. Opening a
connection without specifying the database to use is generally
only useful when building tools that work with multiple
databases, such as GUI database managers.
dbname.tablename.colname
FROM dbname.tablename...
Always use the Connection.setCatalog()
method to specify the desired database in JDBC applications,
rather than the USE
statement.
database
MySQL Connector/J has failover support. This enables the driver
to fail over to any number of slave hosts and still perform
read-only queries. Failover only happens when the connection is
in an autoCommit(true) state, because
failover cannot happen reliably when a
transaction is in
progress. Most application servers and connection pools set
autoCommit to true at the
end of every transaction/connection use.
The failover functionality has the following behavior:
If the URL property autoReconnect is
false: Failover only happens at
connection initialization, and failback occurs when the
driver determines that the first host has become available
again.
If the URL property autoReconnect is
true: Failover happens when the driver
determines that the connection has failed (checked before
every query), and falls back to the
first host when it determines that the host has become
available again (after
queriesBeforeRetryMaster queries have
been issued).
In either case, whenever you are connected to a “failed-over” server, the connection is set to read-only state, so queries that attempt to modify data will throw exceptions (the query will never be processed by the MySQL server).
Configuration properties define how Connector/J will make a
connection to a MySQL server. Unless otherwise noted, properties
can be set for a DataSource object or for a
Connection object.
Configuration properties can be set in one of the following ways:
Using the set*() methods on MySQL
implementations of java.sql.DataSource
(which is the preferred method when using implementations of
java.sql.DataSource):
com.mysql.jdbc.jdbc2.optional.MysqlDataSource
com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource
As a key/value pair in the
java.util.Properties instance passed to
DriverManager.getConnection() or
Driver.connect()
As a JDBC URL parameter in the URL given to
java.sql.DriverManager.getConnection(),
java.sql.Driver.connect() or the MySQL
implementations of the
javax.sql.DataSource
setURL() method.
If the mechanism you use to configure a JDBC URL is XML-based, use the XML character literal & to separate configuration parameters, as the ampersand is a reserved character for XML.
The properties are listed in the following tables.
Connection/Authentication.
| Property Name | Definition | Default Value | Since Version |
user | The user to connect as | | all versions |
password | The password to use when connecting | | all versions |
socketFactory | The name of the class that the driver should use for creating socket connections to the server. This class must implement the interface 'com.mysql.jdbc.SocketFactory' and have public no-args constructor. | com.mysql.jdbc.StandardSocketFactory | 3.0.3 |
connectTimeout | Timeout for socket connect (in milliseconds), with 0 being no timeout. Only works on JDK-1.4 or newer. Defaults to '0'. | 0 | 3.0.1 |
socketTimeout | Timeout on network socket operations (0, the default means no timeout). | 0 | 3.0.1 |
connectionLifecycleInterceptors | A comma-delimited list of classes that implement "com.mysql.jdbc.ConnectionLifecycleInterceptor" that should notified of connection lifecycle events (creation, destruction, commit, rollback, setCatalog and setAutoCommit) and potentially alter the execution of these commands. ConnectionLifecycleInterceptors are "stackable", more than one interceptor may be specified via the configuration property as a comma-delimited list, with the interceptors executed in order from left to right. | | 5.1.4 |
useConfigs | Load the comma-delimited list of configuration properties before parsing the URL or applying user-specified properties. These configurations are explained in the 'Configurations' of the documentation. | | 3.1.5 |
authenticationPlugins | Comma-delimited list of classes that implement com.mysql.jdbc.AuthenticationPlugin and which will be used for authentication unless disabled by "disabledAuthenticationPlugins" property. | | 5.1.19 |
defaultAuthenticationPlugin | Name of a class implementing com.mysql.jdbc.AuthenticationPlugin which will be used as the default authentication plugin (see below). It is an error to use a class which is not listed in "authenticationPlugins" nor it is one of the built-in plugins. It is an error to set as default a plugin which was disabled with "disabledAuthenticationPlugins" property. It is an error to set this value to null or the empty string (i.e. there must be at least a valid default authentication plugin specified for the connection, meeting all constraints listed above). | com.mysql.jdbc.authentication.MysqlNativePasswordPlugin | 5.1.19 |
disabledAuthenticationPlugins | Comma-delimited list of classes implementing com.mysql.jdbc.AuthenticationPlugin or mechanisms, i.e. "mysql_native_password". The authentication plugins or mechanisms listed will not be used for authentication which will fail if it requires one of them. It is an error to disable the default authentication plugin (either the one named by "defaultAuthenticationPlugin" property or the hard-coded one if "defaultAuthenticationPlugin" propery is not set). | | 5.1.19 |
interactiveClient | Set the CLIENT_INTERACTIVE flag, which tells MySQL to timeout connections based on INTERACTIVE_TIMEOUT instead of WAIT_TIMEOUT | false | 3.1.0 |
localSocketAddress | Hostname or IP address given to explicitly configure the interface that the driver will bind the client side of the TCP/IP connection to when connecting. | | 5.0.5 |
propertiesTransform | An implementation of com.mysql.jdbc.ConnectionPropertiesTransform that the driver will use to modify URL properties passed to the driver before attempting a connection | | 3.1.4 |
useCompression | Use zlib compression when communicating with the server (true/false)? Defaults to 'false'. | false | 3.0.17 |
Networking.
| Property Name | Definition | Default Value | Since Version |
maxAllowedPacket | Maximum allowed packet size to send to server. If not set, the value of system variable 'max_allowed_packet' will be used to initialize this upon connecting. This value will not take effect if set larger than the value of 'max_allowed_packet'. | -1 | 5.1.8 |
tcpKeepAlive | If connecting using TCP/IP, should the driver set SO_KEEPALIVE? | true | 5.0.7 |
tcpNoDelay | If connecting using TCP/IP, should the driver set SO_TCP_NODELAY (disabling the Nagle Algorithm)? | true | 5.0.7 |
tcpRcvBuf | If connecting using TCP/IP, should the driver set SO_RCV_BUF to the given value? The default value of '0', means use the platform default value for this property) | 0 | 5.0.7 |
tcpSndBuf | If connecting using TCP/IP, should the driver set SO_SND_BUF to the given value? The default value of '0', means use the platform default value for this property) | 0 | 5.0.7 |
tcpTrafficClass | If connecting using TCP/IP, should the driver set traffic class or type-of-service fields ?See the documentation for java.net.Socket.setTrafficClass() for more information. | 0 | 5.0.7 |
High Availability and Clustering.
| Property Name | Definition | Default Value | Since Version |
autoReconnect | Should the driver try to re-establish stale and/or dead connections? If enabled the driver will throw an exception for a queries issued on a stale or dead connection, which belong to the current transaction, but will attempt reconnect before the next query issued on the connection in a new transaction. The use of this feature is not recommended, because it has side effects related to session state and data consistency when applications don't handle SQLExceptions properly, and is only designed to be used when you are unable to configure your application to handle SQLExceptions resulting from dead and stale connections properly. Alternatively, as a last option, investigate setting the MySQL server variable "wait_timeout" to a high value, rather than the default of 8 hours. | false | 1.1 |
autoReconnectForPools | Use a reconnection strategy appropriate for connection pools (defaults to 'false') | false | 3.1.3 |
failOverReadOnly | When failing over in autoReconnect mode, should the connection be set to 'read-only'? | true | 3.0.12 |
maxReconnects | Maximum number of reconnects to attempt if autoReconnect is true, default is '3'. | 3 | 1.1 |
reconnectAtTxEnd | If autoReconnect is set to true, should the driver attempt reconnections at the end of every transaction? | false | 3.0.10 |
retriesAllDown | When using loadbalancing, the number of times the driver should cycle through available hosts, attempting to connect. Between cycles, the driver will pause for 250ms if no servers are available. | 120 | 5.1.6 |
initialTimeout | If autoReconnect is enabled, the initial time to wait between re-connect attempts (in seconds, defaults to '2'). | 2 | 1.1 |
roundRobinLoadBalance | When autoReconnect is enabled, and failoverReadonly is false, should we pick hosts to connect to on a round-robin basis? | false | 3.1.2 |
queriesBeforeRetryMaster | Number of queries to issue before falling back to master when failed over (when using multi-host failover). Whichever condition is met first, 'queriesBeforeRetryMaster' or 'secondsBeforeRetryMaster' will cause an attempt to be made to reconnect to the master. Defaults to 50. | 50 | 3.0.2 |
secondsBeforeRetryMaster | How long should the driver wait, when failed over, before attempting | 30 | 3.0.2 |
selfDestructOnPingMaxOperations | =If set to a non-zero value, the driver will report close the connection and report failure when Connection.ping() or Connection.isValid(int) is called if the connnection's count of commands sent to the server exceeds this value. | 0 | 5.1.6 |
selfDestructOnPingSecondsLifetime | If set to a non-zero value, the driver will report close the connection and report failure when Connection.ping() or Connection.isValid(int) is called if the connnection's lifetime exceeds this value. | 0 | 5.1.6 |
resourceId | A globally unique name that identifies the resource that this datasource or connection is connected to, used for XAResource.isSameRM() when the driver can't determine this value based on hostnames used in the URL | | 5.0.1 |
Security.
| Property Name | Definition | Default Value | Since Version |
allowMultiQueries | Allow the use of ';' to delimit multiple queries during one statement (true/false), defaults to 'false', and does not affect the addBatch() and executeBatch() methods, which instead rely on rewriteBatchStatements. | false | 3.1.1 |
useSSL | Use SSL when communicating with the server (true/false), defaults to 'false' | false | 3.0.2 |
requireSSL | Require SSL connection if useSSL=true? (defaults to 'false'). | false | 3.1.0 |
verifyServerCertificate | If "useSSL" is set to "true", should the driver verify the server's certificate? When using this feature, the keystore parameters should be specified by the "clientCertificateKeyStore*" properties, rather than system properties. | true | 5.1.6 |
clientCertificateKeyStoreUrl | URL to the client certificate KeyStore (if not specified, use defaults) | | 5.1.0 |
clientCertificateKeyStoreType | KeyStore type for client certificates (NULL or empty means use the default, which is "JKS". Standard keystore types supported by the JVM are "JKS" and "PKCS12", your environment may have more available depending on what security products are installed and available to the JVM. | JKS | 5.1.0 |
clientCertificateKeyStorePassword | Password for the client certificates KeyStore | | 5.1.0 |
trustCertificateKeyStoreUrl | URL to the trusted root certificate KeyStore (if not specified, use defaults) | | 5.1.0 |
trustCertificateKeyStoreType | KeyStore type for trusted root certificates (NULL or empty means use the default, which is "JKS". Standard keystore types supported by the JVM are "JKS" and "PKCS12", your environment may have more available depending on what security products are installed and available to the JVM. | JKS | 5.1.0 |
trustCertificateKeyStorePassword | Password for the trusted root certificates KeyStore | | 5.1.0 |
allowLoadLocalInfile | Should the driver allow use of 'LOAD DATA LOCAL INFILE...' (defaults to 'true'). | true | 3.0.3 |
allowUrlInLocalInfile | Should the driver allow URLs in 'LOAD DATA LOCAL INFILE' statements? | false | 3.1.4 |
paranoid | Take measures to prevent exposure sensitive information in error messages and clear data structures holding sensitive data when possible? (defaults to 'false') | false | 3.0.1 |
passwordCharacterEncoding | What character encoding is used for passwords? Leaving this set to the default value (null), uses the platform character set, which works for ISO8859_1 (i.e. "latin1") passwords. For passwords in other character encodings, the encoding will have to be specified with this property, as it's not possible for the driver to auto-detect this. | | 5.1.7 |
Performance Extensions.
| Property Name | Definition | Default Value | Since Version |
callableStmtCacheSize | If 'cacheCallableStmts' is enabled, how many callable statements should be cached? | 100 | 3.1.2 |
metadataCacheSize | The number of queries to cache ResultSetMetadata for if cacheResultSetMetaData is set to 'true' (default 50) | 50 | 3.1.1 |
useLocalSessionState | Should the driver refer to the internal values of autocommit and transaction isolation that are set by Connection.setAutoCommit() and Connection.setTransactionIsolation() and transaction state as maintained by the protocol, rather than querying the database or blindly sending commands to the database for commit() or rollback() method calls? | false | 3.1.7 |
useLocalTransactionState | Should the driver use the in-transaction state provided by the MySQL protocol to determine if a commit() or rollback() should actually be sent to the database? | false | 5.1.7 |
prepStmtCacheSize | If prepared statement caching is enabled, how many prepared statements should be cached? | 25 | 3.0.10 |
prepStmtCacheSqlLimit | If prepared statement caching is enabled, what's the largest SQL the driver will cache the parsing for? | 256 | 3.0.10 |
parseInfoCacheFactory | Name of a class implementing com.mysql.jdbc.CacheAdapterFactory, which will be used to create caches for the parsed representation of client-side prepared statements. | com.mysql.jdbc.PerConnectionLRUFactory | 5.1.1 |
alwaysSendSetIsolation | Should the driver always communicate with the database when Connection.setTransactionIsolation() is called? If set to false, the driver will only communicate with the database when the requested transaction isolation is different than the whichever is newer, the last value that was set via Connection.setTransactionIsolation(), or the value that was read from the server when the connection was established. Note that useLocalSessionState=true will force the same behavior as alwaysSendSetIsolation=false, regardless of how alwaysSendSetIsolation is set. | true | 3.1.7 |
maintainTimeStats | Should the driver maintain various internal timers to enable idle time calculations as well as more verbose error messages when the connection to the server fails? Setting this property to false removes at least two calls to System.getCurrentTimeMillis() per query. | true | 3.1.9 |
useCursorFetch | If connected to MySQL > 5.0.2, and setFetchSize() > 0 on a statement, should that statement use cursor-based fetching to retrieve rows? | false | 5.0.0 |
blobSendChunkSize | Chunk to use when sending BLOB/CLOBs via ServerPreparedStatements | 1048576 | 3.1.9 |
cacheCallableStmts | Should the driver cache the parsing stage of CallableStatements | false | 3.1.2 |
cachePrepStmts | Should the driver cache the parsing stage of PreparedStatements of client-side prepared statements, the "check" for suitability of server-side prepared and server-side prepared statements themselves? | false | 3.0.10 |
cacheResultSetMetadata | Should the driver cache ResultSetMetaData for Statements and PreparedStatements? (Req. JDK-1.4+, true/false, default 'false') | false | 3.1.1 |
cacheServerConfiguration | Should the driver cache the results of 'SHOW VARIABLES' and 'SHOW COLLATION' on a per-URL basis? | false | 3.1.5 |
defaultFetchSize | The driver will call setFetchSize(n) with this value on all newly-created Statements | 0 | 3.1.9 |
dontTrackOpenResources | The JDBC specification requires the driver to automatically track and close resources, however if your application doesn't do a good job of explicitly calling close() on statements or result sets, this can cause memory leakage. Setting this property to true relaxes this constraint, and can be more memory efficient for some applications. | false | 3.1.7 |
dynamicCalendars | Should the driver retrieve the default calendar when required, or cache it per connection/session? | false | 3.1.5 |
elideSetAutoCommits | If using MySQL-4.1 or newer, should the driver only issue 'set autocommit=n' queries when the server's state doesn't match the requested state by Connection.setAutoCommit(boolean)? | false | 3.1.3 |
enableQueryTimeouts | When enabled, query timeouts set via Statement.setQueryTimeout() use a shared java.util.Timer instance for scheduling. Even if the timeout doesn't expire before the query is processed, there will be memory used by the TimerTask for the given timeout which won't be reclaimed until the time the timeout would have expired if it hadn't been cancelled by the driver. High-load environments might want to consider disabling this functionality. | true | 5.0.6 |
holdResultsOpenOverStatementClose | Should the driver close result sets on Statement.close() as required by the JDBC specification? | false | 3.1.7 |
largeRowSizeThreshold | What size result set row should the JDBC driver consider "large", and thus use a more memory-efficient way of representing the row internally? | 2048 | 5.1.1 |
loadBalanceStrategy | If using a load-balanced connection to connect to SQL nodes in a MySQL Cluster/NDB configuration (by using the URL prefix "jdbc:mysql:loadbalance://"), which load balancing algorithm should the driver use: (1) "random" - the driver will pick a random host for each request. This tends to work better than round-robin, as the randomness will somewhat account for spreading loads where requests vary in response time, while round-robin can sometimes lead to overloaded nodes if there are variations in response times across the workload. (2) "bestResponseTime" - the driver will route the request to the host that had the best response time for the previous transaction. | random | 5.0.6 |
locatorFetchBufferSize | If 'emulateLocators' is configured to 'true', what size buffer should be used when fetching BLOB data for getBinaryInputStream? | 1048576 | 3.2.1 |
rewriteBatchedStatements | Should the driver use multiqueries (irregardless of the setting of "allowMultiQueries") as well as rewriting of prepared statements for INSERT into multi-value inserts when executeBatch() is called? Notice that this has the potential for SQL injection if using plain java.sql.Statements and your code doesn't sanitize input correctly. Notice that for prepared statements, server-side prepared statements can not currently take advantage of this rewrite option, and that if you don't specify stream lengths when using PreparedStatement.set*Stream(), the driver won't be able to determine the optimum number of parameters per batch and you might receive an error from the driver that the resultant packet is too large. Statement.getGeneratedKeys() for these rewritten statements only works when the entire batch includes INSERT statements. | false | 3.1.13 |
useDirectRowUnpack | Use newer result set row unpacking code that skips a copy from network buffers to a MySQL packet instance and instead reads directly into the result set row data buffers. | true | 5.1.1 |
useDynamicCharsetInfo | Should the driver use a per-connection cache of character set information queried from the server when necessary, or use a built-in static mapping that is more efficient, but isn't aware of custom character sets or character sets implemented after the release of the JDBC driver? | true | 5.0.6 |
useFastDateParsing | Use internal String->Date/Time/Timestamp conversion routines to avoid excessive object creation? | true | 5.0.5 |
useFastIntParsing | Use internal String->Integer conversion routines to avoid excessive object creation? | true | 3.1.4 |
useJvmCharsetConverters | Always use the character encoding routines built into the JVM, rather than using lookup tables for single-byte character sets? | false | 5.0.1 |
useReadAheadInput | Use newer, optimized non-blocking, buffered input stream when reading from the server? | true | 3.1.5 |
Debugging/Profiling.
| Property Name | Definition | Default Value | Since Version |
logger | The name of a class that implements "com.mysql.jdbc.log.Log" that will be used to log messages to. (default is "com.mysql.jdbc.log.StandardLogger", which logs to STDERR) | com.mysql.jdbc.log.StandardLogger | 3.1.1 |
gatherPerfMetrics | Should the driver gather performance metrics, and report them via the configured logger every 'reportMetricsIntervalMillis' milliseconds? | false | 3.1.2 |
profileSQL | Trace queries and their execution/fetch times to the configured logger (true/false) defaults to 'false' | false | 3.1.0 |
profileSql | Deprecated, use 'profileSQL' instead. Trace queries and their execution/fetch times on STDERR (true/false) defaults to 'false' | | 2.0.14 |
reportMetricsIntervalMillis | If 'gatherPerfMetrics' is enabled, how often should they be logged (in ms)? | 30000 | 3.1.2 |
maxQuerySizeToLog | Controls the maximum length/size of a query that will get logged when profiling or tracing | 2048 | 3.1.3 |
packetDebugBufferSize | The maximum number of packets to retain when 'enablePacketDebug' is true | 20 | 3.1.3 |
slowQueryThresholdMillis | If 'logSlowQueries' is enabled, how long should a query (in ms) before it is logged as 'slow'? | 2000 | 3.1.2 |
slowQueryThresholdNanos | If 'useNanosForElapsedTime' is set to true, and this property is set to a non-zero value, the driver will use this threshold (in nanosecond units) to determine if a query was slow. | 0 | 5.0.7 |
useUsageAdvisor | Should the driver issue 'usage' warnings advising proper and efficient usage of JDBC and MySQL Connector/J to the log (true/false, defaults to 'false')? | false | 3.1.1 |
autoGenerateTestcaseScript | Should the driver dump the SQL it is executing, including server-side prepared statements to STDERR? | false | 3.1.9 |
autoSlowLog | Instead of using slowQueryThreshold* to determine if a query is slow enough to be logged, maintain statistics that allow the driver to determine queries that are outside the 99th percentile? | true | 5.1.4 |
clientInfoProvider | The name of a class that implements the com.mysql.jdbc.JDBC4ClientInfoProvider interface in order to support JDBC-4.0's Connection.get/setClientInfo() methods | com.mysql.jdbc.JDBC4CommentClientInfoProvider | 5.1.0 |
dumpMetadataOnColumnNotFound | Should the driver dump the field-level metadata of a result set into the exception message when ResultSet.findColumn() fails? | false | 3.1.13 |
dumpQueriesOnException | Should the driver dump the contents of the query sent to the server in the message for SQLExceptions? | false | 3.1.3 |
enablePacketDebug | When enabled, a ring-buffer of 'packetDebugBufferSize' packets will be kept, and dumped when exceptions are thrown in key areas in the driver's code | false | 3.1.3 |
explainSlowQueries | If 'logSlowQueries' is enabled, should the driver automatically issue an 'EXPLAIN' on the server and send the results to the configured log at a WARN level? | false | 3.1.2 |
includeInnodbStatusInDeadlockExceptions | Include the output of "SHOW ENGINE INNODB STATUS" in exception messages when deadlock exceptions are detected? | false | 5.0.7 |
includeThreadDumpInDeadlockExceptions | Include a current Java thread dump in exception messages when deadlock exceptions are detected? | false | 5.1.15 |
includeThreadNamesAsStatementComment | Include the name of the current thread as a comment visible in "SHOW PROCESSLIST", or in Innodb deadlock dumps, useful in correlation with "includeInnodbStatusInDeadlockExceptions=true" and "includeThreadDumpInDeadlockExceptions=true". | false | 5.1.15 |
logSlowQueries | Should queries that take longer than 'slowQueryThresholdMillis' be logged? | false | 3.1.2 |
logXaCommands | Should the driver log XA commands sent by MysqlXaConnection to the server, at the DEBUG level of logging? | false | 5.0.5 |
profilerEventHandler | Name of a class that implements the interface com.mysql.jdbc.profiler.ProfilerEventHandler that will be used to handle profiling/tracing events. | com.mysql.jdbc.profiler.LoggingProfilerEventHandler | 5.1.6 |
resultSetSizeThreshold | If the usage advisor is enabled, how many rows should a result set contain before the driver warns that it is suspiciously large? | 100 | 5.0.5 |
traceProtocol | Should trace-level network protocol be logged? | false | 3.1.2 |
useNanosForElapsedTime | For profiling/debugging functionality that measures elapsed time, should the driver try to use nanoseconds resolution if available (JDK >= 1.5)? | false | 5.0.7 |
Miscellaneous.
| Property Name | Definition | Default Value | Since Version |
useUnicode | Should the driver use Unicode character encodings when handling strings? Should only be used when the driver can't determine the character set mapping, or you are trying to 'force' the driver to use a character set that MySQL either doesn't natively support (such as UTF-8), true/false, defaults to 'true' | true | 1.1g |
characterEncoding | If 'useUnicode' is set to true, what character encoding should the driver use when dealing with strings? (defaults is to 'autodetect') | | 1.1g |
characterSetResults | Character set to tell the server to return results as. | | 3.0.13 |
connectionCollation | If set, tells the server to use this collation via 'set collation_connection' | | 3.0.13 |
useBlobToStoreUTF8OutsideBMP | Tells the driver to treat [MEDIUM/LONG]BLOB columns as [LONG]VARCHAR columns holding text encoded in UTF-8 that has characters outside the BMP (4-byte encodings), which MySQL server can't handle natively. | false | 5.1.3 |
utf8OutsideBmpExcludedColumnNamePattern | When "useBlobToStoreUTF8OutsideBMP" is set to "true", column names matching the given regex will still be treated as BLOBs unless they match the regex specified for "utf8OutsideBmpIncludedColumnNamePattern". The regex must follow the patterns used for the java.util.regex package. | | 5.1.3 |
utf8OutsideBmpIncludedColumnNamePattern | Used to specify exclusion rules to "utf8OutsideBmpExcludedColumnNamePattern". The regex must follow the patterns used for the java.util.regex package. | | 5.1.3 |
loadBalanceEnableJMX | Enables JMX-based management of load-balanced connection groups, including live addition/removal of hosts from load-balancing pool. | false | 5.1.13 |
sessionVariables | A comma-separated list of name/value pairs to be sent as SET SESSION ... to the server when the driver connects. | | 3.1.8 |
useColumnNamesInFindColumn | Prior to JDBC-4.0, the JDBC specification had a bug related to what could be given as a "column name" to ResultSet methods like findColumn(), or getters that took a String property. JDBC-4.0 clarified "column name" to mean the label, as given in an "AS" clause and returned by ResultSetMetaData.getColumnLabel(), and if no AS clause, the column name. Setting this property to "true" will give behavior that is congruent to JDBC-3.0 and earlier versions of the JDBC specification, but which because of the specification bug could give unexpected results. This property is preferred over "useOldAliasMetadataBehavior" unless you need the specific behavior that it provides with respect to ResultSetMetadata. | false | 5.1.7 |
allowNanAndInf | Should the driver allow NaN or +/- INF values in PreparedStatement.setDouble()? | false | 3.1.5 |
autoClosePStmtStreams | Should the driver automatically call .close() on streams/readers passed as arguments via set*() methods? | false | 3.1.12 |
autoDeserialize | Should the driver automatically detect and de-serialize objects stored in BLOB fields? | false | 3.1.5 |
blobsAreStrings | Should the driver always treat BLOBs as Strings - specifically to work around dubious metadata returned by the server for GROUP BY clauses? | false | 5.0.8 |
capitalizeTypeNames | Capitalize type names in DatabaseMetaData? (usually only useful when using WebObjects, true/false, defaults to 'false') | true | 2.0.7 |
clobCharacterEncoding | The character encoding to use for sending and retrieving TEXT, MEDIUMTEXT and LONGTEXT values instead of the configured connection characterEncoding | | 5.0.0 |
clobberStreamingResults | This will cause a 'streaming' ResultSet to be automatically closed, and any outstanding data still streaming from the server to be discarded if another query is executed before all the data has been read from the server. | false | 3.0.9 |
compensateOnDuplicateKeyUpdateCounts | Should the driver compensate for the update counts of "ON DUPLICATE KEY" INSERT statements (2 = 1, 0 = 1) when using prepared statements? | false | 5.1.7 |
continueBatchOnError | Should the driver continue processing batch commands if one statement fails. The JDBC spec allows either way (defaults to 'true'). | true | 3.0.3 |
createDatabaseIfNotExist | Creates the database given in the URL if it doesn't yet exist. Assumes the configured user has permissions to create databases. | false | 3.1.9 |
emptyStringsConvertToZero | Should the driver allow conversions from empty string fields to numeric values of '0'? | true | 3.1.8 |
emulateLocators | Should the driver emulate java.sql.Blobs with locators? With this feature enabled, the driver will delay loading the actual Blob data until the one of the retrieval methods (getInputStream(), getBytes(), and so forth) on the blob data stream has been accessed. For this to work, you must use a column alias with the value of the column to the actual name of the Blob. The feature also has the following restrictions: The SELECT that created the result set must reference only one table, the table must have a primary key; the SELECT must alias the original blob column name, specified as a string, to an alternate name; the SELECT must cover all columns that make up the primary key. | false | 3.1.0 |
emulateUnsupportedPstmts | Should the driver detect prepared statements that are not supported by the server, and replace them with client-side emulated versions? | true | 3.1.7 |
exceptionInterceptors | Comma-delimited list of classes that implement com.mysql.jdbc.ExceptionInterceptor. These classes will be instantiated one per Connection instance, and all SQLExceptions thrown by the driver will be allowed to be intercepted by these interceptors, in a chained fashion, with the first class listed as the head of the chain. | | 5.1.8 |
functionsNeverReturnBlobs | Should the driver always treat data from functions returning BLOBs as Strings - specifically to work around dubious metadata returned by the server for GROUP BY clauses? | false | 5.0.8 |
generateSimpleParameterMetadata | Should the driver generate simplified parameter metadata for PreparedStatements when no metadata is available either because the server couldn't support preparing the statement, or server-side prepared statements are disabled? | false | 5.0.5 |
ignoreNonTxTables | Ignore non-transactional table warning for rollback? (defaults to 'false'). | false | 3.0.9 |
jdbcCompliantTruncation | Should the driver throw java.sql.DataTruncation exceptions when data is truncated as is required by the JDBC specification when connected to a server that supports warnings (MySQL 4.1.0 and newer)? This property has no effect if the server sql-mode includes STRICT_TRANS_TABLES. | true | 3.1.2 |
loadBalanceAutoCommitStatementRegex | When load-balancing is enabled for auto-commit statements (via loadBalanceAutoCommitStatementThreshold), the statement counter will only increment when the SQL matches the regular expression. By default, every statement issued matches. | | 5.1.15 |
loadBalanceAutoCommitStatementThreshold | When auto-commit is enabled, the number of statements which should be executed before triggering load-balancing to rebalance. Default value of 0 causes load-balanced connections to only rebalance when exceptions are encountered, or auto-commit is disabled and transactions are explicitly committed or rolled back. | 0 | 5.1.15 |
loadBalanceBlacklistTimeout | Time in milliseconds between checks of servers which are unavailable, by controlling how long a server lives in the global blacklist. | 0 | 5.1.0 |
loadBalanceConnectionGroup | Logical group of load-balanced connections within a classloader, used to manage different groups independently. If not specified, live management of load-balanced connections is disabled. | | 5.1.13 |
loadBalanceExceptionChecker | Fully-qualified class name of custom exception checker. The class must implement com.mysql.jdbc.LoadBalanceExceptionChecker interface, and is used to inspect SQLExceptions and determine whether they should trigger fail-over to another host in a load-balanced deployment. | com.mysql.jdbc.StandardLoadBalanceExceptionChecker | 5.1.13 |
loadBalancePingTimeout | Time in milliseconds to wait for ping response from each of load-balanced physical connections when using load-balanced Connection. | 0 | 5.1.13 |
loadBalanceSQLExceptionSubclassFailover | Comma-delimited list of classes/interfaces used by default load-balanced exception checker to determine whether a given SQLException should trigger failover. The comparison is done using Class.isInstance(SQLException) using the thrown SQLException. | | 5.1.13 |
loadBalanceSQLStateFailover | Comma-delimited list of SQLState codes used by default load-balanced exception checker to determine whether a given SQLException should trigger failover. The SQLState of a given SQLException is evaluated to determine whether it begins with any value in the comma-delimited list. | | 5.1.13 |
loadBalanceValidateConnectionOnSwapServer | Should the load-balanced Connection explicitly check whether the connection is live when swapping to a new physical connection at commit/rollback? | false | 5.1.13 |
maxRows | The maximum number of rows to return (0, the default means return all rows). | -1 | all versions |
netTimeoutForStreamingResults | What value should the driver automatically set the server setting 'net_write_timeout' to when the streaming result sets feature is in use? (value has unit of seconds, the value '0' means the driver will not try and adjust this value) | 600 | 5.1.0 |
noAccessToProcedureBodies | When determining procedure parameter types for CallableStatements, and the connected user can't access procedure bodies through "SHOW CREATE PROCEDURE" or select on mysql.proc should the driver instead create basic metadata (all parameters reported as IN VARCHARs, but allowing registerOutParameter() to be called on them anyway) instead of throwing an exception? | false | 5.0.3 |
noDatetimeStringSync | Don't ensure that ResultSet.getDatetimeType().toString().equals(ResultSet.getString()) | false | 3.1.7 |
noTimezoneConversionForTimeType | Don't convert TIME values using the server timezone if 'useTimezone'='true' | false | 5.0.0 |
nullCatalogMeansCurrent | When DatabaseMetadataMethods ask for a 'catalog' parameter, does the value null mean use the current catalog? (this is not JDBC-compliant, but follows legacy behavior from earlier versions of the driver) | true | 3.1.8 |
nullNamePatternMatchesAll | Should DatabaseMetaData methods that accept *pattern parameters treat null the same as '%' (this is not JDBC-compliant, however older versions of the driver accepted this departure from the specification) | true | 3.1.8 |
overrideSupportsIntegrityEnhancementFacility | Should the driver return "true" for DatabaseMetaData.supportsIntegrityEnhancementFacility() even if the database doesn't support it to workaround applications that require this method to return "true" to signal support of foreign keys, even though the SQL specification states that this facility contains much more than just foreign key support (one such application being OpenOffice)? | false | 3.1.12 |
padCharsWithSpace | If a result set column has the CHAR type and the value does not fill the amount of characters specified in the DDL for the column, should the driver pad the remaining characters with space (for ANSI compliance)? | false | 5.0.6 |
pedantic | Follow the JDBC spec to the letter. | false | 3.0.0 |
pinGlobalTxToPhysicalConnection | When using XAConnections, should the driver ensure that operations on a given XID are always routed to the same physical connection? This allows the XAConnection to support "XA START ... JOIN" after "XA END" has been called | false | 5.0.1 |
populateInsertRowWithDefaultValues | When using ResultSets that are CONCUR_UPDATABLE, should the driver pre-populate the "insert" row with default values from the DDL for the table used in the query so those values are immediately available for ResultSet accessors? This functionality requires a call to the database for metadata each time a result set of this type is created. If disabled (the default), the default values will be populated by the an internal call to refreshRow() which pulls back default values and/or values changed by triggers. | false | 5.0.5 |
processEscapeCodesForPrepStmts | Should the driver process escape codes in queries that are prepared? | true | 3.1.12 |
queryTimeoutKillsConnection | If the timeout given in Statement.setQueryTimeout() expires, should the driver forcibly abort the Connection instead of attempting to abort the query? | false | 5.1.9 |
relaxAutoCommit | If the version of MySQL the driver connects to does not support transactions, still allow calls to commit(), rollback() and setAutoCommit() (true/false, defaults to 'false')? | false | 2.0.13 |
retainStatementAfterResultSetClose | Should the driver retain the Statement reference in a ResultSet after ResultSet.close() has been called. This is not JDBC-compliant after JDBC-4.0. | false | 3.1.11 |
rollbackOnPooledClose | Should the driver issue a rollback() when the logical connection in a pool is closed? | true | 3.0.15 |
runningCTS13 | Enables workarounds for bugs in Sun's JDBC compliance testsuite version 1.3 | false | 3.1.7 |
serverTimezone | Override detection/mapping of timezone. Used when timezone from server doesn't map to Java timezone | | 3.0.2 |
statementInterceptors | A comma-delimited list of classes that implement "com.mysql.jdbc.StatementInterceptor" that should be placed "in between" query execution to influence the results. StatementInterceptors are "chainable", the results returned by the "current" interceptor will be passed on to the next in in the chain, from left-to-right order, as specified in this property. | | 5.1.1 |
strictFloatingPoint | Used only in older versions of compliance test | false | 3.0.0 |
strictUpdates | Should the driver do strict checking (all primary keys selected) of updatable result sets (true, false, defaults to 'true')? | true | 3.0.4 |
tinyInt1isBit | Should the driver treat the datatype TINYINT(1) as the BIT type (because the server silently converts BIT -> TINYINT(1) when creating tables)? | true | 3.0.16 |
transformedBitIsBoolean | If the driver converts TINYINT(1) to a different type, should it use BOOLEAN instead of BIT for future compatibility with MySQL-5.0, as MySQL-5.0 has a BIT type? | false | 3.1.9 |
treatUtilDateAsTimestamp | Should the driver treat java.util.Date as a TIMESTAMP for the purposes of PreparedStatement.setObject()? | true | 5.0.5 |
ultraDevHack | Create PreparedStatements for prepareCall() when required, because UltraDev is broken and issues a prepareCall() for _all_ statements? (true/false, defaults to 'false') | false | 2.0.3 |
useAffectedRows | Don't set the CLIENT_FOUND_ROWS flag when connecting to the server (not JDBC-compliant, will break most applications that rely on "found" rows vs. "affected rows" for DML statements), but does cause "correct" update counts from "INSERT ... ON DUPLICATE KEY UPDATE" statements to be returned by the server. | false | 5.1.7 |
useGmtMillisForDatetimes | Convert between session timezone and GMT before creating Date and Timestamp instances (value of "false" is legacy behavior, "true" leads to more JDBC-compliant behavior. | false | 3.1.12 |
useHostsInPrivileges | Add '@hostname' to users in DatabaseMetaData.getColumn/TablePrivileges() (true/false), defaults to 'true'. | true | 3.0.2 |
useInformationSchema | When connected to MySQL-5.0.7 or newer, should the driver use the INFORMATION_SCHEMA to derive information used by DatabaseMetaData? | false | 5.0.0 |
useJDBCCompliantTimezoneShift | Should the driver use JDBC-compliant rules when converting TIME/TIMESTAMP/DATETIME values' timezone information for those JDBC arguments which take a java.util.Calendar argument? (Notice that this option is exclusive of the "useTimezone=true" configuration option.) | false | 5.0.0 |
useLegacyDatetimeCode | Use code for DATE/TIME/DATETIME/TIMESTAMP handling in result sets and statements that consistently handles timezone conversions from client to server and back again, or use the legacy code for these datatypes that has been in the driver for backwards-compatibility? | true | 5.1.6 |
useOldAliasMetadataBehavior | Should the driver use the legacy behavior for "AS" clauses on columns and tables, and only return aliases (if any) for ResultSetMetaData.getColumnName() or ResultSetMetaData.getTableName() rather than the original column/table name? In 5.0.x, the default value was true. | false | 5.0.4 |
useOldUTF8Behavior | Use the UTF-8 behavior the driver did when communicating with 4.0 and older servers | false | 3.1.6 |
useOnlyServerErrorMessages | Don't prepend 'standard' SQLState error messages to error messages returned by the server. | true | 3.0.15 |
useSSPSCompatibleTimezoneShift | If migrating from an environment that was using server-side prepared statements, and the configuration property "useJDBCCompliantTimeZoneShift" set to "true", use compatible behavior when not using server-side prepared statements when sending TIMESTAMP values to the MySQL server. | false | 5.0.5 |
useServerPrepStmts | Use server-side prepared statements if the server supports them? | false | 3.1.0 |
useSqlStateCodes | Use SQL Standard state codes instead of 'legacy' X/Open/SQL state codes (true/false), default is 'true' | true | 3.1.3 |
useStreamLengthsInPrepStmts | Honor stream length parameter in PreparedStatement/ResultSet.setXXXStream() method calls (true/false, defaults to 'true')? | true | 3.0.2 |
useTimezone | Convert time/date types between client and server timezones (true/false, defaults to 'false')? | false | 3.0.2 |
useUnbufferedInput | Don't use BufferedInputStream for reading data from the server | true | 3.0.11 |
yearIsDateType | Should the JDBC driver treat the MySQL type "YEAR" as a java.sql.Date, or as a SHORT? | true | 3.1.9 |
zeroDateTimeBehavior | What should happen when the driver encounters DATETIME values that are composed entirely of zeros (used by MySQL to represent invalid dates)? Valid values are "exception", "round" and "convertToNull". | exception | 3.1.4 |
Connector/J also supports access to MySQL using named pipes on
Windows NT, Windows 2000, or Windows XP using the
NamedPipeSocketFactory as a plugin-socket
factory using the socketFactory property. If
you do not use a namedPipePath property, the
default of '\\.\pipe\MySQL' is used. If you
use the NamedPipeSocketFactory, the host name
and port number values in the JDBC url are ignored. To enable
this feature, use:
socketFactory=com.mysql.jdbc.NamedPipeSocketFactory
Named pipes only work when connecting to a MySQL server on the same physical machine where the JDBC driver is running. In simple performance tests, named pipe access is between 30%-50% faster than the standard TCP/IP access. However, this varies per system, and named pipes are slower than TCP/IP in many Windows configurations.
To create your own socket factories, follow the example code in
com.mysql.jdbc.NamedPipeSocketFactory, or
com.mysql.jdbc.StandardSocketFactory.
The useConfigs connection option is a
convenient shorthand for specifying combinations of options
for particular scenarios. The argument values you can use with
this option correspond to the names of
.properties files within the Connector/J
mysql-connector-java-
JAR file. For example, the Connector/J 5.1.9 driver includes
the following configuration properties files:
version-bin.jar
$ unzip mysql-connector-java-5.1.19-bin.jar '*/configs/*' Archive: mysql-connector-java-5.1.19-bin.jar creating: com/mysql/jdbc/configs/ inflating: com/mysql/jdbc/configs/3-0-Compat.properties inflating: com/mysql/jdbc/configs/5-0-Compat.properties inflating: com/mysql/jdbc/configs/clusterBase.properties inflating: com/mysql/jdbc/configs/coldFusion.properties inflating: com/mysql/jdbc/configs/fullDebug.properties inflating: com/mysql/jdbc/configs/maxPerformance.properties inflating: com/mysql/jdbc/configs/solarisMaxPerformance.properties
To specify one of these combinations of options, specify
useConfigs=3-0-Compat,
useConfigs=maxPerformance, and so on. The
following sections show the options that are part of each
useConfigs setting. For the details of why
each one is included, see the comments in the
.properties files.
emptyStringsConvertToZero=true jdbcCompliantTruncation=false noDatetimeStringSync=true nullCatalogMeansCurrent=true nullNamePatternMatchesAll=true transformedBitIsBoolean=false dontTrackOpenResources=true zeroDateTimeBehavior=convertToNull useServerPrepStmts=false autoClosePStmtStreams=true processEscapeCodesForPrepStmts=false useFastDateParsing=false populateInsertRowWithDefaultValues=false useDirectRowUnpack=false
useDirectRowUnpack=false
autoReconnect=true failOverReadOnly=false roundRobinLoadBalance=true
useDynamicCharsetInfo=false alwaysSendSetIsolation=false useLocalSessionState=true autoReconnect=true
profileSQL=true gatherPerMetrics=true useUsageAdvisor=true logSlowQueries=true explainSlowQueries=true
cachePrepStmts=true cacheCallableStmts=true cacheServerConfiguration=true useLocalSessionState=true elideSetAutoCommits=true alwaysSendSetIsolation=false enableQueryTimeouts=false
useUnbufferedInput=false useReadAheadInput=false maintainTimeStats=false
MySQL Connector/J passes all of the tests in the publicly available version of Sun's JDBC compliance test suite. This section gives details on a interface-by-interface level about implementation decisions that might affect how you code applications with MySQL Connector/J. The JDBC specification is vague about how certain functionality should be implemented, or the specification enables leeway in implementation.
BLOB
Starting with Connector/J version 3.1.0, you can emulate
BLOBs with locators by adding the property
emulateLocators=true to your JDBC URL.
Using this method, the driver will delay loading the actual
BLOB data until you retrieve the other data and then use
retrieval methods (getInputStream(),
getBytes(), and so forth) on the BLOB
data stream.
You must use a column alias with the value of the column to the actual name of the BLOB, for example:
SELECT id, 'data' as blob_data from blobtable
You must also follow these rules:
The SELECT must reference
only one table. The table must have a
primary key.
The SELECT must alias the
original BLOB column name, specified as a string, to an
alternate name.
The SELECT must cover all
columns that make up the primary key.
The BLOB implementation does not allow in-place modification
(they are copies, as reported by the
DatabaseMetaData.locatorsUpdateCopies()
method). Because of this, use the corresponding
PreparedStatement.setBlob() or
ResultSet.updateBlob() (in the case of
updatable result sets) methods to save changes back to the
database.
CallableStatement
Starting with Connector/J 3.1.1, stored procedures are
supported when connecting to MySQL version 5.0 or newer
using the CallableStatement
interface. Currently, the
getParameterMetaData() method of
CallableStatement is not supported.
CLOB
The CLOB implementation does not allow in-place modification
(they are copies, as reported by the
DatabaseMetaData.locatorsUpdateCopies()
method). Because of this, use the
PreparedStatement.setClob() method to
save changes back to the database. The JDBC API does not
have a ResultSet.updateClob() method.
Connection
Unlike the pre-Connector/J JDBC driver
(MM.MySQL), the
isClosed() method does not ping the
server to determine if it is available. In accordance with
the JDBC specification, it only returns true if
closed() has been called on the
connection. If you need to determine if the connection is
still valid, issue a simple query, such as SELECT
1. The driver will throw an exception if the
connection is no longer valid.
DatabaseMetaData
Foreign key
information
(getImportedKeys()/getExportedKeys()
and getCrossReference()) is only
available from InnoDB tables.
The driver uses SHOW CREATE
TABLE to retrieve this information, so if any
other storage engines add support for foreign keys, the
driver would transparently support them as well.
PreparedStatement
PreparedStatements are implemented by the driver, as MySQL
does not have a prepared statement feature. Because of this,
the driver does not implement
getParameterMetaData() or
getMetaData() as it would require the
driver to have a complete SQL parser in the client.
Starting with version 3.1.0 MySQL Connector/J, server-side prepared statements and binary-encoded result sets are used when the server supports them.
Take care when using a server-side prepared statement with
large parameters that are
set using setBinaryStream(),
setAsciiStream(),
setUnicodeStream(),
setBlob(), or
setClob(). To re-execute the statement
with any large parameter changed to a nonlarge parameter,
call clearParameters() and set all
parameters again. The reason for this is as follows:
During both server-side prepared statements and
client-side emulation, large data is exchanged only when
PreparedStatement.execute() is
called.
Once that has been done, the stream used to read the data on the client side is closed (as per the JDBC spec), and cannot be read from again.
If a parameter changes from large to nonlarge, the
driver must reset the server-side state of the prepared
statement to allow the parameter that is being changed
to take the place of the prior large value. This removes
all of the large data that has already been sent to the
server, thus requiring the data to be re-sent, using the
setBinaryStream(),
setAsciiStream(),
setUnicodeStream(),
setBlob() or
setClob() method.
Consequently, to change the type of a parameter to a
nonlarge one, you must call
clearParameters() and set all
parameters of the prepared statement again before it can be
re-executed.
ResultSet
By default, ResultSets are completely retrieved and stored in memory. In most cases this is the most efficient way to operate, and due to the design of the MySQL network protocol is easier to implement. If you are working with ResultSets that have a large number of rows or large values, and cannot allocate heap space in your JVM for the memory required, you can tell the driver to stream the results back one row at a time.
To enable this functionality, create a
Statement instance in the following
manner:
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
java.sql.ResultSet.CONCUR_READ_ONLY);
stmt.setFetchSize(Integer.MIN_VALUE);
The combination of a forward-only, read-only result set,
with a fetch size of Integer.MIN_VALUE
serves as a signal to the driver to stream result sets
row-by-row. After this, any result sets created with the
statement will be retrieved row-by-row.
There are some caveats with this approach. You must read all of the rows in the result set (or close it) before you can issue any other queries on the connection, or an exception will be thrown.
The earliest the locks these statements hold can be released
(whether they be MyISAM table-level locks
or row-level locks in some other storage engine such as
InnoDB) is when the statement completes.
If the statement is within scope of a transaction, then locks are released when the transaction completes (which implies that the statement needs to complete first). As with most other databases, statements are not complete until all the results pending on the statement are read or the active result set for the statement is closed.
Therefore, if using streaming results, process them as quickly as possible if you want to maintain concurrent access to the tables referenced by the statement producing the result set.
ResultSetMetaData
The isAutoIncrement() method only works
when using MySQL servers 4.0 and newer.
Statement
When using versions of the JDBC driver earlier than 3.2.1,
and connected to server versions earlier than 5.0.3, the
setFetchSize() method has no effect,
other than to toggle result set streaming as described
above.
Connector/J 5.0.0 and later include support for both
Statement.cancel() and
Statement.setQueryTimeout(). Both require
MySQL 5.0.0 or newer server, and require a separate
connection to issue the
KILL QUERY
statement. In the case of
setQueryTimeout(), the implementation
creates an additional thread to handle the timeout
functionality.
Failures to cancel the statement for
setQueryTimeout() may manifest
themselves as RuntimeException rather
than failing silently, as there is currently no way to
unblock the thread that is executing the query being
cancelled due to timeout expiration and have it throw the
exception instead.
The MySQL statement
KILL QUERY
(which is what the driver uses to implement
Statement.cancel()) is
non-deterministic; thus, avoid the use of
Statement.cancel() if possible. If no
query is in process, the next query issued will be killed
by the server. This race condition is guarded against as
of Connector/J 5.1.18.
MySQL does not support SQL cursors, and the JDBC driver
doesn't emulate them, so setCursorName()
has no effect.
Connector/J 5.1.3 and later include two additional methods:
setLocalInfileInputStream() sets an
InputStream instance that will be
used to send data to the MySQL server for a
LOAD DATA
LOCAL INFILE statement rather than a
FileInputStream or
URLInputStream that represents the
path given as an argument to the statement.
This stream will be read to completion upon execution of
a LOAD DATA
LOCAL INFILE statement, and will automatically
be closed by the driver, so it needs to be reset before
each call to execute*() that would
cause the MySQL server to request data to fulfill the
request for
LOAD DATA
LOCAL INFILE.
If this value is set to NULL, the
driver will revert to using a
FileInputStream or
URLInputStream as required.
getLocalInfileInputStream() returns
the InputStream instance that will be
used to send data in response to a
LOAD DATA
LOCAL INFILE statement.
This method returns NULL if no such
stream has been set using
setLocalInfileInputStream().
MySQL Connector/J is flexible in the way it handles conversions between MySQL data types and Java data types.
In general, any MySQL data type can be converted to a
java.lang.String, and any numeric type can be
converted to any of the Java numeric types, although round-off,
overflow, or loss of precision may occur.
All TEXT types return
Types.LONGVARCHAR with different
getPrecision() values (65535, 255,
16777215, and 2147483647 respectively) with
getColumnType() returning
-1. This behavior is intentional even
though TINYTEXT does not fall, regarding to
its size, within the LONGVARCHAR category.
This is to avoid different handling inside the same base type.
And getColumnType() returns
-1 because the internal server handling is
of type TEXT, which is similar to
BLOB.
Also note that getColumnTypeName() will
return VARCHAR even though
getColumnType() returns
Types.LONGVARCHAR, because
VARCHAR is the designated column
database-specific name for this type.
Starting with Connector/J 3.1.0, the JDBC driver issues warnings
or throws DataTruncation exceptions as is
required by the JDBC specification unless the connection was
configured not to do so by using the property
jdbcCompliantTruncation and setting it to
false.
The conversions that are always guaranteed to work are listed in the following table:
Connection Properties - Miscellaneous.
| These MySQL Data Types | Can always be converted to these Java types |
|---|---|
CHAR, VARCHAR, BLOB, TEXT, ENUM, and SET | java.lang.String, java.io.InputStream, java.io.Reader,
java.sql.Blob, java.sql.Clob |
FLOAT, REAL, DOUBLE PRECISION, NUMERIC, DECIMAL, TINYINT,
SMALLINT, MEDIUMINT, INTEGER, BIGINT | java.lang.String, java.lang.Short, java.lang.Integer,
java.lang.Long, java.lang.Double,
java.math.BigDecimal |
DATE, TIME, DATETIME, TIMESTAMP | java.lang.String, java.sql.Date, java.sql.Timestamp |
Round-off, overflow or loss of precision may occur if you choose a Java numeric data type that has less precision or capacity than the MySQL data type you are converting to/from.
The ResultSet.getObject() method uses the
type conversions between MySQL and Java types, following the
JDBC specification where appropriate. The value returned by
ResultSetMetaData.GetColumnClassName() is
also shown below. For more information on the
java.sql.Types classes see
Java
2 Platform Types.
MySQL Types to Java Types for ResultSet.getObject().
| MySQL Type Name | Return value of GetColumnClassName | Returned as Java Class |
|---|---|---|
BIT(1) (new in MySQL-5.0) | BIT | java.lang.Boolean |
BIT( > 1) (new in MySQL-5.0) | BIT | byte[] |
TINYINT | TINYINT | java.lang.Boolean if the configuration property
tinyInt1isBit is set to
true (the default) and the
storage size is 1, or
java.lang.Integer if not. |
BOOL, BOOLEAN | TINYINT | See TINYINT, above as these are aliases for
TINYINT(1), currently. |
SMALLINT[(M)] [UNSIGNED] | SMALLINT [UNSIGNED] | java.lang.Integer (regardless if
UNSIGNED or not) |
MEDIUMINT[(M)] [UNSIGNED] | MEDIUMINT [UNSIGNED] | java.lang.Integer, if UNSIGNED
java.lang.Long (C/J 3.1 and
earlier), or
java.lang.Integer for C/J 5.0
and later |
INT,INTEGER[(M)] [UNSIGNED] | INTEGER [UNSIGNED] | java.lang.Integer, if UNSIGNED
java.lang.Long |
BIGINT[(M)] [UNSIGNED] | BIGINT [UNSIGNED] | java.lang.Long, if UNSIGNED
java.math.BigInteger |
FLOAT[(M,D)] | FLOAT | java.lang.Float |
DOUBLE[(M,B)] | DOUBLE | java.lang.Double |
DECIMAL[(M[,D])] | DECIMAL | java.math.BigDecimal |
DATE | DATE | java.sql.Date |
DATETIME | DATETIME | java.sql.Timestamp |
TIMESTAMP[(M)] | TIMESTAMP | java.sql.Timestamp |
TIME | TIME | java.sql.Time |
YEAR[(2|4)] | YEAR | If yearIsDateType configuration property is set to
false, then the returned object
type is java.sql.Short. If
set to true (the default), then
the returned object is of type
java.sql.Date with the date
set to January 1st, at midnight. |
CHAR(M) | CHAR | java.lang.String (unless the character set for
the column is BINARY, then
byte[] is returned. |
VARCHAR(M) [BINARY] | VARCHAR | java.lang.String (unless the character set for
the column is BINARY, then
byte[] is returned. |
BINARY(M) | BINARY | byte[] |
VARBINARY(M) | VARBINARY | byte[] |
TINYBLOB | TINYBLOB | byte[] |
TINYTEXT | VARCHAR | java.lang.String |
BLOB | BLOB | byte[] |
TEXT | VARCHAR | java.lang.String |
MEDIUMBLOB | MEDIUMBLOB | byte[] |
MEDIUMTEXT | VARCHAR | java.lang.String |
LONGBLOB | LONGBLOB | byte[] |
LONGTEXT | VARCHAR | java.lang.String |
ENUM('value1','value2',...) | CHAR | java.lang.String |
SET('value1','value2',...) | CHAR | java.lang.String |
All strings sent from the JDBC driver to the server are
converted automatically from native Java Unicode form to the
client character encoding, including all queries sent using
Statement.execute(),
Statement.executeUpdate(),
Statement.executeQuery() as well as all
PreparedStatement and
CallableStatement parameters with
the exclusion of parameters set using
setBytes(),
setBinaryStream(),
setAsciiStream(),
setUnicodeStream() and
setBlob().
In MySQL Server 4.1 and higher, Connector/J supports a single
character encoding between client and server, and any number of
character encodings for data returned by the server to the
client in ResultSets.
Prior to MySQL Server 4.1, Connector/J supported a single
character encoding per connection, which could either be
automatically detected from the server configuration, or could
be configured by the user through the
useUnicode and
characterEncoding properties.
The character encoding between client and server is
automatically detected upon connection. You specify the encoding
on the server using the
character_set_server for server
versions 4.1.0 and newer, and character_set
system variable for server versions older than 4.1.0. The driver
automatically uses the encoding specified by the server. For
more information, see Server Character Set and Collation.
For example, to use 4-byte UTF-8 character sets with
Connector/J, configure the MySQL server with
character_set_server=utf8mb4,
and leave characterEncoding out of the
Connector/J connection string. Connector/J will then autodetect
the UTF-8 setting.
To override the automatically detected encoding on the client
side, use the characterEncoding property
in the URL used to connect to the server.
To allow multiple character sets to be sent from the client, use
the UTF-8 encoding, either by configuring
utf8 as the default server character set, or
by configuring the JDBC driver to use UTF-8 through the
characterEncoding property.
When specifying character encodings on the client side, use Java-style names. The following table lists Java-style names for MySQL character sets:
MySQL to Java Encoding Name Translations.
| MySQL Character Set Name | Java-Style Character Encoding Name |
|---|---|
ascii | US-ASCII |
big5 | Big5 |
gbk | GBK |
sjis | SJIS (or Cp932 or MS932 for MySQL Server < 4.1.11) |
cp932 | Cp932 or MS932 (MySQL Server > 4.1.11) |
gb2312 | EUC_CN |
ujis | EUC_JP |
euckr | EUC_KR |
latin1 | Cp1252 |
latin2 | ISO8859_2 |
greek | ISO8859_7 |
hebrew | ISO8859_8 |
cp866 | Cp866 |
tis620 | TIS620 |
cp1250 | Cp1250 |
cp1251 | Cp1251 |
cp1257 | Cp1257 |
macroman | MacRoman |
macce | MacCentralEurope |
utf8 | UTF-8 |
ucs2 | UnicodeBig |
Do not issue the query set names with
Connector/J, as the driver will not detect that the character
set has changed, and will continue to use the character set
detected during the initial connection setup.
SSL in MySQL Connector/J encrypts all data (other than the initial handshake) between the JDBC driver and the server. The performance penalty for enabling SSL is an increase in query processing time between 35% and 50%, depending on the size of the query, and the amount of data it returns.
For SSL Support to work, you must have the following:
A JDK that includes JSSE (Java Secure Sockets Extension), like JDK-1.4.1 or newer. SSL does not currently work with a JDK that you can add JSSE to, like JDK-1.2.x or JDK-1.3.x due to the following JSSE bug: http://developer.java.sun.com/developer/bugParade/bugs/4273544.html
A MySQL server that supports SSL and has been compiled and configured to do so, which is MySQL 4.0.4 or later, see Using SSL for Secure Connections for more information.
A client certificate (covered later in this section)
The system works through two Java truststore files, one file
contains the certificate information for the server
(truststore in the examples below). The
other file contains the certificate for the client
(keystore in the examples below). All Java
truststore files are password protected by supplying a suitable
password to the keytool when you create the
files. You need the file names and associated passwords to
create an SSL connection.
You will first need to import the MySQL server CA Certificate
into a Java truststore. A sample MySQL server CA Certificate is
located in the SSL subdirectory of the
MySQL source distribution. This is what SSL will use to
determine if you are communicating with a secure MySQL server.
Alternatively, use the CA Certificate that you have generated or
been provided with by your SSL provider.
To use Java's keytool to create a truststore
in the current directory , and import the server's CA
certificate (cacert.pem), you can do the
following (assuming that keytool is in your
path. The keytool is typically located in the
bin subdirectory of your JDK or JRE):
shell> keytool -import -alias mysqlServerCACert \ -file cacert.pem -keystore truststore
Enter the password when prompted for the keystore file. Interaction with keytool looks like this:
Enter keystore password: *********
Owner: EMAILADDRESS=walrus@example.com, CN=Walrus,
O=MySQL AB, L=Orenburg, ST=Some-State, C=RU
Issuer: EMAILADDRESS=walrus@example.com, CN=Walrus,
O=MySQL AB, L=Orenburg, ST=Some-State, C=RU
Serial number: 0
Valid from:
Fri Aug 02 16:55:53 CDT 2002 until: Sat Aug 02 16:55:53 CDT 2003
Certificate fingerprints:
MD5: 61:91:A0:F2:03:07:61:7A:81:38:66:DA:19:C4:8D:AB
SHA1: 25:77:41:05:D5:AD:99:8C:14:8C:CA:68:9C:2F:B8:89:C3:34:4D:6C
Trust this certificate? [no]: yes
Certificate was added to keystoreYou then have two options: either import the client certificate that matches the CA certificate you just imported, or create a new client certificate.
Importing an existing certificate requires the certificate to be in DER format. You can use openssl to convert an existing certificate into the new format. For example:
shell> openssl x509 -outform DER -in client-cert.pem -out client.cert
Now import the converted certificate into your keystore using keytool:
shell> keytool -import -file client.cert -keystore keystore -alias mysqlClientCertificate
To generate your own client certificate, use
keytool to create a suitable certificate and
add it to the keystore file:
shell> keytool -genkey -keyalg rsa \
-alias mysqlClientCertificate -keystore keystore
Keytool will prompt you for the following information, and
create a keystore named keystore in the
current directory.
Respond with information that is appropriate for your situation:
Enter keystore password: *********
What is your first and last name?
[Unknown]: Matthews
What is the name of your organizational unit?
[Unknown]: Software Development
What is the name of your organization?
[Unknown]: MySQL AB
What is the name of your City or Locality?
[Unknown]: Flossmoor
What is the name of your State or Province?
[Unknown]: IL
What is the two-letter country code for this unit?
[Unknown]: US
Is <CN=Matthews, OU=Software Development, O=MySQL AB,
L=Flossmoor, ST=IL, C=US> correct?
[no]: y
Enter key password for <mysqlClientCertificate>
(RETURN if same as keystore password):
Finally, to get JSSE to use the keystore and truststore that you
have generated, you need to set the following system properties
when you start your JVM, replacing
path_to_keystore_file with the full
path to the keystore file you created,
path_to_truststore_file with the path
to the truststore file you created, and using the appropriate
password values for each property. You can do this either on the
command line:
-Djavax.net.ssl.keyStore=path_to_keystore_file-Djavax.net.ssl.keyStorePassword=password-Djavax.net.ssl.trustStore=path_to_truststore_file-Djavax.net.ssl.trustStorePassword=password
Or you can set the values directly within the application:
System.setProperty("javax.net.ssl.keyStore","path_to_keystore_file");
System.setProperty("javax.net.ssl.keyStorePassword","password");
System.setProperty("javax.net.ssl.trustStore","path_to_truststore_file");
System.setProperty("javax.net.ssl.trustStorePassword","password");
You will also need to set useSSL to
true in your connection parameters for MySQL
Connector/J, either by adding useSSL=true to
your URL, or by setting the property useSSL
to true in the
java.util.Properties instance you pass to
DriverManager.getConnection().
You can test that SSL is working by turning on JSSE debugging (as detailed below), and look for the following key events:
...
*** ClientHello, v3.1
RandomCookie: GMT: 1018531834 bytes = { 199, 148, 180, 215, 74, 12, »
54, 244, 0, 168, 55, 103, 215, 64, 16, 138, 225, 190, 132, 153, 2, »
217, 219, 239, 202, 19, 121, 78 }
Session ID: {}
Cipher Suites: { 0, 5, 0, 4, 0, 9, 0, 10, 0, 18, 0, 19, 0, 3, 0, 17 }
Compression Methods: { 0 }
***
[write] MD5 and SHA1 hashes: len = 59
0000: 01 00 00 37 03 01 3D B6 90 FA C7 94 B4 D7 4A 0C ...7..=.......J.
0010: 36 F4 00 A8 37 67 D7 40 10 8A E1 BE 84 99 02 D9 6...7g.@........
0020: DB EF CA 13 79 4E 00 00 10 00 05 00 04 00 09 00 ....yN..........
0030: 0A 00 12 00 13 00 03 00 11 01 00 ...........
main, WRITE: SSL v3.1 Handshake, length = 59
main, READ: SSL v3.1 Handshake, length = 74
*** ServerHello, v3.1
RandomCookie: GMT: 1018577560 bytes = { 116, 50, 4, 103, 25, 100, 58, »
202, 79, 185, 178, 100, 215, 66, 254, 21, 83, 187, 190, 42, 170, 3, »
132, 110, 82, 148, 160, 92 }
Session ID: {163, 227, 84, 53, 81, 127, 252, 254, 178, 179, 68, 63, »
182, 158, 30, 11, 150, 79, 170, 76, 255, 92, 15, 226, 24, 17, 177, »
219, 158, 177, 187, 143}
Cipher Suite: { 0, 5 }
Compression Method: 0
***
%% Created: [Session-1, SSL_RSA_WITH_RC4_128_SHA]
** SSL_RSA_WITH_RC4_128_SHA
[read] MD5 and SHA1 hashes: len = 74
0000: 02 00 00 46 03 01 3D B6 43 98 74 32 04 67 19 64 ...F..=.C.t2.g.d
0010: 3A CA 4F B9 B2 64 D7 42 FE 15 53 BB BE 2A AA 03 :.O..d.B..S..*..
0020: 84 6E 52 94 A0 5C 20 A3 E3 54 35 51 7F FC FE B2 .nR..\ ..T5Q....
0030: B3 44 3F B6 9E 1E 0B 96 4F AA 4C FF 5C 0F E2 18 .D?.....O.L.\...
0040: 11 B1 DB 9E B1 BB 8F 00 05 00 ..........
main, READ: SSL v3.1 Handshake, length = 1712
...
JSSE provides debugging (to stdout) when you
set the following system property:
-Djavax.net.debug=all This will tell you what
keystores and truststores are being used, as well as what is
going on during the SSL handshake and certificate exchange. It
will be helpful when trying to determine what is not working
when trying to get an SSL connection to happen.
Connector/J 3.1.7 and higher includes a variant of the driver
that will automatically send queries to a read/write master, or
a failover or round-robin loadbalanced set of slaves based on
the state of Connection.getReadOnly().
An application signals that it wants a transaction to be
read-only by calling
Connection.setReadOnly(true), this
replication-aware connection will use one of the slave
connections, which are load-balanced per-vm using a round-robin
scheme (a given connection is sticky to a slave unless that
slave is removed from service). If you have a write transaction,
or if you have a read that is time-sensitive (remember,
replication in MySQL is asynchronous), set the connection to be
not read-only, by calling
Connection.setReadOnly(false) and the driver
will ensure that further calls are sent to the master MySQL
server. The driver takes care of propagating the current state
of autocommit, isolation level, and catalog between all of the
connections that it uses to accomplish this load balancing
functionality.
To enable this functionality, use the
com.mysql.jdbc.ReplicationDriver class when
configuring your application server's connection pool or when
creating an instance of a JDBC driver for your standalone
application. Because it accepts the same URL format as the
standard MySQL JDBC driver, ReplicationDriver
does not currently work with
java.sql.DriverManager-based connection
creation unless it is the only MySQL JDBC driver registered with
the DriverManager .
Here is a short example of how
ReplicationDriver might be used in a
standalone application:
import java.sql.Connection;
import java.sql.ResultSet;
import java.util.Properties;
import com.mysql.jdbc.ReplicationDriver;
public class ReplicationDriverDemo {
public static void main(String[] args) throws Exception {
ReplicationDriver driver = new ReplicationDriver();
Properties props = new Properties();
// We want this for failover on the slaves
props.put("autoReconnect", "true");
// We want to load balance between the slaves
props.put("roundRobinLoadBalance", "true");
props.put("user", "foo");
props.put("password", "bar");
//
// Looks like a normal MySQL JDBC url, with a
// comma-separated list of hosts, the first
// being the 'master', the rest being any number
// of slaves that the driver will load balance against
//
Connection conn =
driver.connect("jdbc:mysql:replication://master,slave1,slave2,slave3/test",
props);
//
// Perform read/write work on the master
// by setting the read-only flag to "false"
//
conn.setReadOnly(false);
conn.setAutoCommit(false);
conn.createStatement().executeUpdate("UPDATE some_table ....");
conn.commit();
//
// Now, do a query from a slave, the driver automatically picks one
// from the list
//
conn.setReadOnly(true);
ResultSet rs =
conn.createStatement().executeQuery("SELECT a,b FROM alt_table");
.......
}
}Consider investigating the Load Balancing JDBC Pool (lbpool) tool, which provides a wrapper around the standard JDBC driver and enables you to use DB connection pools that includes checks for system failures and uneven load distribution. For more information, see Load Balancing JDBC Pool (lbpool).
The table below provides a mapping of the MySQL error numbers to
JDBC SQLState values.
Table 5.1. Mapping of MySQL Error Numbers to SQLStates
| MySQL Error Number | MySQL Error Name | Legacy (X/Open) SQLState | SQL Standard SQLState |
|---|---|---|---|
| 1022 | ER_DUP_KEY | S1000 | 23000 |
| 1037 | ER_OUTOFMEMORY | S1001 | HY001 |
| 1038 | ER_OUT_OF_SORTMEMORY | S1001 | HY001 |
| 1040 | ER_CON_COUNT_ERROR | 08004 | 08004 |
| 1042 | ER_BAD_HOST_ERROR | 08004 | 08S01 |
| 1043 | ER_HANDSHAKE_ERROR | 08004 | 08S01 |
| 1044 | ER_DBACCESS_DENIED_ERROR | S1000 | 42000 |
| 1045 | ER_ACCESS_DENIED_ERROR | 28000 | 28000 |
| 1047 | ER_UNKNOWN_COM_ERROR | 08S01 | HY000 |
| 1050 | ER_TABLE_EXISTS_ERROR | S1000 | 42S01 |
| 1051 | ER_BAD_TABLE_ERROR | 42S02 | 42S02 |
| 1052 | ER_NON_UNIQ_ERROR | S1000 | 23000 |
| 1053 | ER_SERVER_SHUTDOWN | S1000 | 08S01 |
| 1054 | ER_BAD_FIELD_ERROR | S0022 | 42S22 |
| 1055 | ER_WRONG_FIELD_WITH_GROUP | S1009 | 42000 |
| 1056 | ER_WRONG_GROUP_FIELD | S1009 | 42000 |
| 1057 | ER_WRONG_SUM_SELECT | S1009 | 42000 |
| 1058 | ER_WRONG_VALUE_COUNT | 21S01 | 21S01 |
| 1059 | ER_TOO_LONG_IDENT | S1009 | 42000 |
| 1060 | ER_DUP_FIELDNAME | S1009 | 42S21 |
| 1061 | ER_DUP_KEYNAME | S1009 | 42000 |
| 1062 | ER_DUP_ENTRY | S1009 | 23000 |
| 1063 | ER_WRONG_FIELD_SPEC | S1009 | 42000 |
| 1064 | ER_PARSE_ERROR | 42000 | 42000 |
| 1065 | ER_EMPTY_QUERY | 42000 | 42000 |
| 1066 | ER_NONUNIQ_TABLE | S1009 | 42000 |
| 1067 | ER_INVALID_DEFAULT | S1009 | 42000 |
| 1068 | ER_MULTIPLE_PRI_KEY | S1009 | 42000 |
| 1069 | ER_TOO_MANY_KEYS | S1009 | 42000 |
| 1070 | ER_TOO_MANY_KEY_PARTS | S1009 | 42000 |
| 1071 | ER_TOO_LONG_KEY | S1009 | 42000 |
| 1072 | ER_KEY_COLUMN_DOES_NOT_EXITS | S1009 | 42000 |
| 1073 | ER_BLOB_USED_AS_KEY | S1009 | 42000 |
| 1074 | ER_TOO_BIG_FIELDLENGTH | S1009 | 42000 |
| 1075 | ER_WRONG_AUTO_KEY | S1009 | 42000 |
| 1080 | ER_FORCING_CLOSE | S1000 | 08S01 |
| 1081 | ER_IPSOCK_ERROR | 08S01 | 08S01 |
| 1082 | ER_NO_SUCH_INDEX | S1009 | 42S12 |
| 1083 | ER_WRONG_FIELD_TERMINATORS | S1009 | 42000 |
| 1084 | ER_BLOBS_AND_NO_TERMINATED | S1009 | 42000 |
| 1090 | ER_CANT_REMOVE_ALL_FIELDS | S1000 | 42000 |
| 1091 | ER_CANT_DROP_FIELD_OR_KEY | S1000 | 42000 |
| 1101 | ER_BLOB_CANT_HAVE_DEFAULT | S1000 | 42000 |
| 1102 | ER_WRONG_DB_NAME | S1000 | 42000 |
| 1103 | ER_WRONG_TABLE_NAME | S1000 | 42000 |
| 1104 | ER_TOO_BIG_SELECT | S1000 | 42000 |
| 1106 | ER_UNKNOWN_PROCEDURE | S1000 | 42000 |
| 1107 | ER_WRONG_PARAMCOUNT_TO_PROCEDURE | S1000 | 42000 |
| 1109 | ER_UNKNOWN_TABLE | S1000 | 42S02 |
| 1110 | ER_FIELD_SPECIFIED_TWICE | S1000 | 42000 |
| 1112 | ER_UNSUPPORTED_EXTENSION | S1000 | 42000 |
| 1113 | ER_TABLE_MUST_HAVE_COLUMNS | S1000 | 42000 |
| 1115 | ER_UNKNOWN_CHARACTER_SET | S1000 | 42000 |
| 1118 | ER_TOO_BIG_ROWSIZE | S1000 | 42000 |
| 1120 | ER_WRONG_OUTER_JOIN | S1000 | 42000 |
| 1121 | ER_NULL_COLUMN_IN_INDEX | S1000 | 42000 |
| 1129 | ER_HOST_IS_BLOCKED | 08004 | HY000 |
| 1130 | ER_HOST_NOT_PRIVILEGED | 08004 | HY000 |
| 1131 | ER_PASSWORD_ANONYMOUS_USER | S1000 | 42000 |
| 1132 | ER_PASSWORD_NOT_ALLOWED | S1000 | 42000 |
| 1133 | ER_PASSWORD_NO_MATCH | S1000 | 42000 |
| 1136 | ER_WRONG_VALUE_COUNT_ON_ROW | S1000 | 21S01 |
| 1138 | ER_INVALID_USE_OF_NULL | S1000 | 42000 |
| 1139 | ER_REGEXP_ERROR | S1000 | 42000 |
| 1140 | ER_MIX_OF_GROUP_FUNC_AND_FIELDS | S1000 | 42000 |
| 1141 | ER_NONEXISTING_GRANT | S1000 | 42000 |
| 1142 | ER_TABLEACCESS_DENIED_ERROR | S1000 | 42000 |
| 1143 | ER_COLUMNACCESS_DENIED_ERROR | S1000 | 42000 |
| 1144 | ER_ILLEGAL_GRANT_FOR_TABLE | S1000 | 42000 |
| 1145 | ER_GRANT_WRONG_HOST_OR_USER | S1000 | 42000 |
| 1146 | ER_NO_SUCH_TABLE | S1000 | 42S02 |
| 1147 | ER_NONEXISTING_TABLE_GRANT | S1000 | 42000 |
| 1148 | ER_NOT_ALLOWED_COMMAND | S1000 | 42000 |
| 1149 | ER_SYNTAX_ERROR | S1000 | 42000 |
| 1152 | ER_ABORTING_CONNECTION | S1000 | 08S01 |
| 1153 | ER_NET_PACKET_TOO_LARGE | S1000 | 08S01 |
| 1154 | ER_NET_READ_ERROR_FROM_PIPE | S1000 | 08S01 |
| 1155 | ER_NET_FCNTL_ERROR | S1000 | 08S01 |
| 1156 | ER_NET_PACKETS_OUT_OF_ORDER | S1000 | 08S01 |
| 1157 | ER_NET_UNCOMPRESS_ERROR | S1000 | 08S01 |
| 1158 | ER_NET_READ_ERROR | S1000 | 08S01 |
| 1159 | ER_NET_READ_INTERRUPTED | S1000 | 08S01 |
| 1160 | ER_NET_ERROR_ON_WRITE | S1000 | 08S01 |
| 1161 | ER_NET_WRITE_INTERRUPTED | S1000 | 08S01 |
| 1162 | ER_TOO_LONG_STRING | S1000 | 42000 |
| 1163 | ER_TABLE_CANT_HANDLE_BLOB | S1000 | 42000 |
| 1164 | ER_TABLE_CANT_HANDLE_AUTO_INCREMENT | S1000 | 42000 |
| 1166 | ER_WRONG_COLUMN_NAME | S1000 | 42000 |
| 1167 | ER_WRONG_KEY_COLUMN | S1000 | 42000 |
| 1169 | ER_DUP_UNIQUE | S1000 | 23000 |
| 1170 | ER_BLOB_KEY_WITHOUT_LENGTH | S1000 | 42000 |
| 1171 | ER_PRIMARY_CANT_HAVE_NULL | S1000 | 42000 |
| 1172 | ER_TOO_MANY_ROWS | S1000 | 42000 |
| 1173 | ER_REQUIRES_PRIMARY_KEY | S1000 | 42000 |
| 1177 | ER_CHECK_NO_SUCH_TABLE | S1000 | 42000 |
| 1178 | ER_CHECK_NOT_IMPLEMENTED | S1000 | 42000 |
| 1179 | ER_CANT_DO_THIS_DURING_AN_TRANSACTION | S1000 | 25000 |
| 1184 | ER_NEW_ABORTING_CONNECTION | S1000 | 08S01 |
| 1189 | ER_MASTER_NET_READ | S1000 | 08S01 |
| 1190 | ER_MASTER_NET_WRITE | S1000 | 08S01 |
| 1203 | ER_TOO_MANY_USER_CONNECTIONS | S1000 | 42000 |
| 1205 | ER_LOCK_WAIT_TIMEOUT | 41000 | 41000 |
| 1207 | ER_READ_ONLY_TRANSACTION | S1000 | 25000 |
| 1211 | ER_NO_PERMISSION_TO_CREATE_USER | S1000 | 42000 |
| 1213 | ER_LOCK_DEADLOCK | 41000 | 40001 |
| 1216 | ER_NO_REFERENCED_ROW | S1000 | 23000 |
| 1217 | ER_ROW_IS_REFERENCED | S1000 | 23000 |
| 1218 | ER_CONNECT_TO_MASTER | S1000 | 08S01 |
| 1222 | ER_WRONG_NUMBER_OF_COLUMNS_IN_SELECT | S1000 | 21000 |
| 1226 | ER_USER_LIMIT_REACHED | S1000 | 42000 |
| 1230 | ER_NO_DEFAULT | S1000 | 42000 |
| 1231 | ER_WRONG_VALUE_FOR_VAR | S1000 | 42000 |
| 1232 | ER_WRONG_TYPE_FOR_VAR | S1000 | 42000 |
| 1234 | ER_CANT_USE_OPTION_HERE | S1000 | 42000 |
| 1235 | ER_NOT_SUPPORTED_YET | S1000 | 42000 |
| 1239 | ER_WRONG_FK_DEF | S1000 | 42000 |
| 1241 | ER_OPERAND_COLUMNS | S1000 | 21000 |
| 1242 | ER_SUBQUERY_NO_1_ROW | S1000 | 21000 |
| 1247 | ER_ILLEGAL_REFERENCE | S1000 | 42S22 |
| 1248 | ER_DERIVED_MUST_HAVE_ALIAS | S1000 | 42000 |
| 1249 | ER_SELECT_REDUCED | S1000 | 01000 |
| 1250 | ER_TABLENAME_NOT_ALLOWED_HERE | S1000 | 42000 |
| 1251 | ER_NOT_SUPPORTED_AUTH_MODE | S1000 | 08004 |
| 1252 | ER_SPATIAL_CANT_HAVE_NULL | S1000 | 42000 |
| 1253 | ER_COLLATION_CHARSET_MISMATCH | S1000 | 42000 |
| 1261 | ER_WARN_TOO_FEW_RECORDS | S1000 | 01000 |
| 1262 | ER_WARN_TOO_MANY_RECORDS | S1000 | 01000 |
| 1263 | ER_WARN_NULL_TO_NOTNULL | S1000 | 01000 |
| 1264 | ER_WARN_DATA_OUT_OF_RANGE | S1000 | 01000 |
| 1265 | ER_WARN_DATA_TRUNCATED | S1000 | 01000 |
| 1280 | ER_WRONG_NAME_FOR_INDEX | S1000 | 42000 |
| 1281 | ER_WRONG_NAME_FOR_CATALOG | S1000 | 42000 |
| 1286 | ER_UNKNOWN_STORAGE_ENGINE | S1000 | 42000 |
Table of Contents
This section provides some general JDBC background.
When you are using JDBC outside of an application server, the
DriverManager class manages the establishment
of Connections.
Specify to the DriverManager which JDBC
drivers to try to make Connections with. The easiest way to do
this is to use Class.forName() on the class
that implements the java.sql.Driver
interface. With MySQL Connector/J, the name of this class is
com.mysql.jdbc.Driver. With this method, you
could use an external configuration file to supply the driver
class name and driver parameters to use when connecting to a
database.
The following section of Java code shows how you might register
MySQL Connector/J from the main() method of
your application. If testing this code, first read the
installation section at
Chapter 3, Connector/J Installation, to make sure you have
connector installed correctly and the
CLASSPATH set up. Also, ensure that MySQL is
configured to accept external TCP/IP connections.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
// Notice, do not import com.mysql.jdbc.*
// or you will have problems!
public class LoadDriver {
public static void main(String[] args) {
try {
// The newInstance() call is a work around for some
// broken Java implementations
Class.forName("com.mysql.jdbc.Driver").newInstance();
} catch (Exception ex) {
// handle the error
}
}
}
After the driver has been registered with the
DriverManager, you can obtain a
Connection instance that is connected to a
particular database by calling
DriverManager.getConnection():
Example 6.1. Connector/J: Obtaining a connection from the
DriverManager
If you have not already done so, please review the section
Section 6.1, “Connecting to MySQL Using the JDBC DriverManager
Interface”
before working with these examples.
This example shows how you can obtain a
Connection instance from the
DriverManager. There are a few different
signatures for the getConnection()
method. Consult the API documentation that comes with your JDK
for more specific information on how to use them.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
Connection conn = null;
...
try {
conn =
DriverManager.getConnection("jdbc:mysql://localhost/test?" +
"user=monty&password=greatsqldb");
// Do something with the Connection
...
} catch (SQLException ex) {
// handle any errors
System.out.println("SQLException: " + ex.getMessage());
System.out.println("SQLState: " + ex.getSQLState());
System.out.println("VendorError: " + ex.getErrorCode());
}
Once a Connection is established, it
can be used to create Statement and
PreparedStatement objects, as well as
retrieve metadata about the database. This is explained in the
following sections.
Statement objects allow you to execute
basic SQL queries and retrieve the results through the
ResultSet class, which is described later.
To create a Statement instance, you call
the createStatement() method on the
Connection object you have retrieved using
one of the DriverManager.getConnection() or
DataSource.getConnection() methods described
earlier.
Once you have a Statement instance, you
can execute a SELECT query by
calling the executeQuery(String) method
with the SQL you want to use.
To update data in the database, use the
executeUpdate(String SQL) method. This
method returns the number of rows matched by the update
statement, not the number of rows that were modified.
If you do not know ahead of time whether the SQL statement will
be a SELECT or an
UPDATE/INSERT,
then you can use the execute(String SQL)
method. This method will return true if the SQL query was a
SELECT, or false if it was an
UPDATE,
INSERT, or
DELETE statement. If the
statement was a SELECT query, you
can retrieve the results by calling the
getResultSet() method. If the statement was
an UPDATE,
INSERT, or
DELETE statement, you can
retrieve the affected rows count by calling
getUpdateCount() on the
Statement instance.
Example 6.2. Connector/J: Using java.sql.Statement to execute a
SELECT query
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
// assume that conn is an already created JDBC connection (see previous examples)
Statement stmt = null;
ResultSet rs = null;
try {
stmt = conn.createStatement();
rs = stmt.executeQuery("SELECT foo FROM bar");
// or alternatively, if you don't know ahead of time that
// the query will be a SELECT...
if (stmt.execute("SELECT foo FROM bar")) {
rs = stmt.getResultSet();
}
// Now do something with the ResultSet ....
}
catch (SQLException ex){
// handle any errors
System.out.println("SQLException: " + ex.getMessage());
System.out.println("SQLState: " + ex.getSQLState());
System.out.println("VendorError: " + ex.getErrorCode());
}
finally {
// it is a good idea to release
// resources in a finally{} block
// in reverse-order of their creation
// if they are no-longer needed
if (rs != null) {
try {
rs.close();
} catch (SQLException sqlEx) { } // ignore
rs = null;
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException sqlEx) { } // ignore
stmt = null;
}
}
Starting with MySQL server version 5.0 when used with
Connector/J 3.1.1 or newer, the
java.sql.CallableStatement interface is
fully implemented with the exception of the
getParameterMetaData() method.
For more information on MySQL stored procedures, please refer to http://dev.mysql.com/doc/mysql/en/stored-routines.html.
Connector/J exposes stored procedure functionality through
JDBC's CallableStatement interface.
Current versions of MySQL server do not return enough
information for the JDBC driver to provide result set metadata
for callable statements. This means that when using
CallableStatement,
ResultSetMetaData may return
NULL.
The following example shows a stored procedure that returns the
value of inOutParam incremented by 1, and the
string passed in using inputParam as a
ResultSet:
Example 6.3. Connector/J: Calling Stored Procedures
CREATE PROCEDURE demoSp(IN inputParam VARCHAR(255), \
INOUT inOutParam INT)
BEGIN
DECLARE z INT;
SET z = inOutParam + 1;
SET inOutParam = z;
SELECT inputParam;
SELECT CONCAT('zyxw', inputParam);
END
To use the demoSp procedure with Connector/J,
follow these steps:
Prepare the callable statement by using
Connection.prepareCall().
Notice that you have to use JDBC escape syntax, and that the parentheses surrounding the parameter placeholders are not optional:
Example 6.4. Connector/J: Using Connection.prepareCall()
import java.sql.CallableStatement;
...
//
// Prepare a call to the stored procedure 'demoSp'
// with two parameters
//
// Notice the use of JDBC-escape syntax ({call ...})
//
CallableStatement cStmt = conn.prepareCall("{call demoSp(?, ?)}");
cStmt.setString(1, "abcdefg");
Connection.prepareCall() is an
expensive method, due to the metadata retrieval that the
driver performs to support output parameters. For
performance reasons, minimize unnecessary calls to
Connection.prepareCall() by reusing
CallableStatement instances in your
code.
Register the output parameters (if any exist)
To retrieve the values of output parameters (parameters
specified as OUT or
INOUT when you created the stored
procedure), JDBC requires that they be specified before
statement execution using the various
registerOutputParameter() methods in
the CallableStatement interface:
Example 6.5. Connector/J: Registering output parameters
import java.sql.Types;
...
//
// Connector/J supports both named and indexed
// output parameters. You can register output
// parameters using either method, as well
// as retrieve output parameters using either
// method, regardless of what method was
// used to register them.
//
// The following examples show how to use
// the various methods of registering
// output parameters (you should of course
// use only one registration per parameter).
//
//
// Registers the second parameter as output, and
// uses the type 'INTEGER' for values returned from
// getObject()
//
cStmt.registerOutParameter(2, Types.INTEGER);
//
// Registers the named parameter 'inOutParam', and
// uses the type 'INTEGER' for values returned from
// getObject()
//
cStmt.registerOutParameter("inOutParam", Types.INTEGER);
...
Set the input parameters (if any exist)
Input and in/out parameters are set as for
PreparedStatement objects. However,
CallableStatement also supports
setting parameters by name:
Example 6.6. Connector/J: Setting CallableStatement input
parameters
...
//
// Set a parameter by index
//
cStmt.setString(1, "abcdefg");
//
// Alternatively, set a parameter using
// the parameter name
//
cStmt.setString("inputParameter", "abcdefg");
//
// Set the 'in/out' parameter using an index
//
cStmt.setInt(2, 1);
//
// Alternatively, set the 'in/out' parameter
// by name
//
cStmt.setInt("inOutParam", 1);
...
Execute the CallableStatement, and
retrieve any result sets or output parameters.
Although CallableStatement supports
calling any of the Statement execute
methods (executeUpdate(),
executeQuery() or
execute()), the most flexible method to
call is execute(), as you do not need
to know ahead of time if the stored procedure returns result
sets:
Example 6.7. Connector/J: Retrieving results and output parameter values
...
boolean hadResults = cStmt.execute();
//
// Process all returned result sets
//
while (hadResults) {
ResultSet rs = cStmt.getResultSet();
// process result set
...
hadResults = cStmt.getMoreResults();
}
//
// Retrieve output parameters
//
// Connector/J supports both index-based and
// name-based retrieval
//
int outputValue = cStmt.getInt(2); // index-based
outputValue = cStmt.getInt("inOutParam"); // name-based
...
Before version 3.0 of the JDBC API, there was no standard way of
retrieving key values from databases that supported auto
increment or identity columns. With older JDBC drivers for
MySQL, you could always use a MySQL-specific method on the
Statement interface, or issue the query
SELECT LAST_INSERT_ID() after issuing an
INSERT to a table that had an
AUTO_INCREMENT key. Using the MySQL-specific
method call isn't portable, and issuing a
SELECT to get the
AUTO_INCREMENT key's value requires another
round-trip to the database, which isn't as efficient as
possible. The following code snippets demonstrate the three
different ways to retrieve AUTO_INCREMENT
values. First, we demonstrate the use of the new JDBC 3.0 method
getGeneratedKeys() which is now the
preferred method to use if you need to retrieve
AUTO_INCREMENT keys and have access to JDBC
3.0. The second example shows how you can retrieve the same
value using a standard SELECT
LAST_INSERT_ID() query. The final example shows how
updatable result sets can retrieve the
AUTO_INCREMENT value when using the
insertRow() method.
Example 6.8. Connector/J: Retrieving AUTO_INCREMENT column values
using Statement.getGeneratedKeys()
Statement stmt = null;
ResultSet rs = null;
try {
//
// Create a Statement instance that we can use for
// 'normal' result sets assuming you have a
// Connection 'conn' to a MySQL database already
// available
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
java.sql.ResultSet.CONCUR_UPDATABLE);
//
// Issue the DDL queries for the table for this example
//
stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
stmt.executeUpdate(
"CREATE TABLE autoIncTutorial ("
+ "priKey INT NOT NULL AUTO_INCREMENT, "
+ "dataField VARCHAR(64), PRIMARY KEY (priKey))");
//
// Insert one row that will generate an AUTO INCREMENT
// key in the 'priKey' field
//
stmt.executeUpdate(
"INSERT INTO autoIncTutorial (dataField) "
+ "values ('Can I Get the Auto Increment Field?')",
Statement.RETURN_GENERATED_KEYS);
//
// Example of using Statement.getGeneratedKeys()
// to retrieve the value of an auto-increment
// value
//
int autoIncKeyFromApi = -1;
rs = stmt.getGeneratedKeys();
if (rs.next()) {
autoIncKeyFromApi = rs.getInt(1);
} else {
// throw an exception from here
}
rs.close();
rs = null;
System.out.println("Key returned from getGeneratedKeys():"
+ autoIncKeyFromApi);
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException ex) {
// ignore
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException ex) {
// ignore
}
}
}Example 6.9. Connector/J: Retrieving AUTO_INCREMENT column values
using SELECT LAST_INSERT_ID()
Statement stmt = null;
ResultSet rs = null;
try {
//
// Create a Statement instance that we can use for
// 'normal' result sets.
stmt = conn.createStatement();
//
// Issue the DDL queries for the table for this example
//
stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
stmt.executeUpdate(
"CREATE TABLE autoIncTutorial ("
+ "priKey INT NOT NULL AUTO_INCREMENT, "
+ "dataField VARCHAR(64), PRIMARY KEY (priKey))");
//
// Insert one row that will generate an AUTO INCREMENT
// key in the 'priKey' field
//
stmt.executeUpdate(
"INSERT INTO autoIncTutorial (dataField) "
+ "values ('Can I Get the Auto Increment Field?')");
//
// Use the MySQL LAST_INSERT_ID()
// function to do the same thing as getGeneratedKeys()
//
int autoIncKeyFromFunc = -1;
rs = stmt.executeQuery("SELECT LAST_INSERT_ID()");
if (rs.next()) {
autoIncKeyFromFunc = rs.getInt(1);
} else {
// throw an exception from here
}
rs.close();
System.out.println("Key returned from " +
"'SELECT LAST_INSERT_ID()': " +
autoIncKeyFromFunc);
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException ex) {
// ignore
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException ex) {
// ignore
}
}
}Example 6.10. Connector/J: Retrieving AUTO_INCREMENT column values
in Updatable ResultSets
Statement stmt = null;
ResultSet rs = null;
try {
//
// Create a Statement instance that we can use for
// 'normal' result sets as well as an 'updatable'
// one, assuming you have a Connection 'conn' to
// a MySQL database already available
//
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
java.sql.ResultSet.CONCUR_UPDATABLE);
//
// Issue the DDL queries for the table for this example
//
stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
stmt.executeUpdate(
"CREATE TABLE autoIncTutorial ("
+ "priKey INT NOT NULL AUTO_INCREMENT, "
+ "dataField VARCHAR(64), PRIMARY KEY (priKey))");
//
// Example of retrieving an AUTO INCREMENT key
// from an updatable result set
//
rs = stmt.executeQuery("SELECT priKey, dataField "
+ "FROM autoIncTutorial");
rs.moveToInsertRow();
rs.updateString("dataField", "AUTO INCREMENT here?");
rs.insertRow();
//
// the driver adds rows at the end
//
rs.last();
//
// We should now be on the row we just inserted
//
int autoIncKeyFromRS = rs.getInt("priKey");
rs.close();
rs = null;
System.out.println("Key returned for inserted row: "
+ autoIncKeyFromRS);
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException ex) {
// ignore
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException ex) {
// ignore
}
}
}Running the preceding example code should produce the following output:
Key returned from getGeneratedKeys(): 1 Key returned from SELECT LAST_INSERT_ID(): 1 Key returned for inserted row: 2
At times, it can be tricky to use the SELECT
LAST_INSERT_ID() query, as that function's value is
scoped to a connection. So, if some other query happens on the
same connection, the value is overwritten. On the other hand,
the getGeneratedKeys() method is scoped by
the Statement instance, so it can be used
even if other queries happen on the same connection, but not on
the same Statement instance.
Connection pooling is a technique of creating and managing a pool of connections that are ready for use by any thread that needs them. Connection pooling can greatly increase the performance of your Java application, while reducing overall resource usage.
Most applications only need a thread to have access to a JDBC connection when they are actively processing a transaction, which often takes only milliseconds to complete. When not processing a transaction, the connection sits idle. Connection pooling enables the idle connection to be used by some other thread to do useful work.
In practice, when a thread needs to do work against a MySQL or other database with JDBC, it requests a connection from the pool. When the thread is finished using the connection, it returns it to the pool, so that it can be used by any other threads.
When the connection is loaned out from the pool, it is used
exclusively by the thread that requested it. From a programming
point of view, it is the same as if your thread called
DriverManager.getConnection() every time it
needed a JDBC connection. With connection pooling, your thread may
end up using either a new connection or an already-existing
connection.
The main benefits to connection pooling are:
Reduced connection creation time.
Although this is not usually an issue with the quick connection setup that MySQL offers compared to other databases, creating new JDBC connections still incurs networking and JDBC driver overhead that will be avoided if connections are recycled.
Simplified programming model.
When using connection pooling, each individual thread can act as though it has created its own JDBC connection, allowing you to use straightforward JDBC programming techniques.
Controlled resource usage.
If you create a new connection every time a thread needs one, rather than using connection pooling, your application's resource usage can be wasteful and lead to unpredictable behavior under load.
Sun has standardized the concept of connection pooling in JDBC through the JDBC 2.0 Optional interfaces, and all major application servers have implementations of these APIs that work with MySQL Connector/J.
Generally, you configure a connection pool in your application server configuration files, and access it through the Java Naming and Directory Interface (JNDI). The following code shows how you might use a connection pool from an application deployed in a J2EE application server:
Example 7.1. Connector/J: Using a connection pool with a J2EE application server
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import javax.naming.InitialContext;
import javax.sql.DataSource;
public class MyServletJspOrEjb {
public void doSomething() throws Exception {
/*
* Create a JNDI Initial context to be able to
* lookup the DataSource
*
* In production-level code, this should be cached as
* an instance or static variable, as it can
* be quite expensive to create a JNDI context.
*
* Note: This code only works when you are using servlets
* or EJBs in a J2EE application server. If you are
* using connection pooling in standalone Java code, you
* will have to create/configure datasources using whatever
* mechanisms your particular connection pooling library
* provides.
*/
InitialContext ctx = new InitialContext();
/*
* Lookup the DataSource, which will be backed by a pool
* that the application server provides. DataSource instances
* are also a good candidate for caching as an instance
* variable, as JNDI lookups can be expensive as well.
*/
DataSource ds =
(DataSource)ctx.lookup("java:comp/env/jdbc/MySQLDB");
/*
* The following code is what would actually be in your
* Servlet, JSP or EJB 'service' method...where you need
* to work with a JDBC connection.
*/
Connection conn = null;
Statement stmt = null;
try {
conn = ds.getConnection();
/*
* Now, use normal JDBC programming to work with
* MySQL, making sure to close each resource when you're
* finished with it, which permits the connection pool
* resources to be recovered as quickly as possible
*/
stmt = conn.createStatement();
stmt.execute("SOME SQL QUERY");
stmt.close();
stmt = null;
conn.close();
conn = null;
} finally {
/*
* close any jdbc instances here that weren't
* explicitly closed during normal code path, so
* that we don't 'leak' resources...
*/
if (stmt != null) {
try {
stmt.close();
} catch (sqlexception sqlex) {
// ignore, as we can't do anything about it here
}
stmt = null;
}
if (conn != null) {
try {
conn.close();
} catch (sqlexception sqlex) {
// ignore, as we can't do anything about it here
}
conn = null;
}
}
}
}
As shown in the example above, after obtaining the JNDI
InitialContext, and looking up the
DataSource, the rest of the code follows
familiar JDBC conventions.
When using connection pooling, always make sure that connections, and anything created by them (such as statements or result sets) are closed. This rule applies no matter what happens in your code (exceptions, flow-of-control, and so forth). When these objects are closed, they can be re-used; otherwise, they will be stranded, which means that the MySQL server resources they represent (such as buffers, locks, or sockets) are tied up for some time, or in the worst case can be tied up forever.
Each connection to MySQL has overhead (memory, CPU, context switches, and so forth) on both the client and server side. Every connection limits how many resources there are available to your application as well as the MySQL server. Many of these resources will be used whether or not the connection is actually doing any useful work! Connection pools can be tuned to maximize performance, while keeping resource utilization below the point where your application will start to fail rather than just run slower.
The optimal size for the connection pool depends on anticipated load and average database transaction time. In practice, the optimal connection pool size can be smaller than you might expect. If you take Sun's Java Petstore blueprint application for example, a connection pool of 15-20 connections can serve a relatively moderate load (600 concurrent users) using MySQL and Tomcat with acceptable response times.
To correctly size a connection pool for your application, create load test scripts with tools such as Apache JMeter or The Grinder, and load test your application.
An easy way to determine a starting point is to configure your connection pool's maximum number of connections to be unbounded, run a load test, and measure the largest amount of concurrently used connections. You can then work backward from there to determine what values of minimum and maximum pooled connections give the best performance for your particular application.
MySQL Connector/J can validate the connection by executing a lightweight ping against a server. In the case of load-balanced connections, this is performed against all active pooled internal connections that are retained. This is beneficial to Java applications using connection pools, as the pool can use this feature to validate connections. Depending on your connection pool and configuration, this validation can be carried out at different times:
Before the pool returns a connection to the application.
When the application returns a connection to the pool.
During periodic checks of idle connections.
To use this feature, specify a validation query in your connection
pool that starts with /* ping */. Note that the
syntax must be exactly as specified. This will cause the driver
send a ping to the server and return a dummy lightweight result
set. When using a ReplicationConnection or
LoadBalancedConnection, the ping will be sent
across all active connections.
It is critical that the syntax be specified correctly. The syntax needs to be exact for reasons of efficiency, as this test is done for every statement that is executed:
protected static final String PING_MARKER = "/* ping */";
...
if (sql.charAt(0) == '/') {
if (sql.startsWith(PING_MARKER)) {
doPingInstead();
...
None of the following snippets will work, because the ping syntax is sensitive to whitespace, capitalization, and placement:
sql = "/* PING */ SELECT 1"; sql = "SELECT 1 /* ping*/"; sql = "/*ping*/ SELECT 1"; sql = " /* ping */ SELECT 1"; sql = "/*to ping or not to ping*/ SELECT 1";
All of the previous statements will issue a normal
SELECT statement and will
not be transformed into the
lightweight ping. Further, for load-balanced connections, the
statement will be executed against one connection in the internal
pool, rather than validating each underlying physical connection.
This results in the non-active physical connections assuming a
stale state, and they may die. If Connector/J then re-balances, it
might select a dead connection, resulting in an exception being
passed to the application. To help prevent this, you can use
loadBalanceValidateConnectionOnSwapServer to
validate the connection before use.
If your Connector/J deployment uses a connection pool that allows
you to specify a validation query, take advantage of it, but
ensure that the query starts exactly with
/* ping */. This is particularly important if
you are using the load-balancing or replication-aware features of
Connector/J, as it will help keep alive connections which
otherwise will go stale and die, causing problems later.
Connector/J has long provided an effective means to distribute read/write load across multiple MySQL server instances for Cluster or master-master replication deployments. Starting with Connector/J 5.1.3, you can now dynamically configure load-balanced connections, with no service outage. In-process transactions are not lost, and no application exceptions are generated if any application is trying to use that particular server instance.
There are two connection string options associated with this functionality:
loadBalanceConnectionGroup – This
provides the ability to group connections from different
sources. This allows you to manage these JDBC sources within a
single class loader in any combination you choose. If they use
the same configuration, and you want to manage them as a
logical single group, give them the same name. This is the key
property for management: if you do not define a name (string)
for loadBalanceConnectionGroup, you cannot
manage the connections. All load-balanced connections sharing
the same loadBalanceConnectionGroup value,
regardless of how the application creates them, will be
managed together.
loadBalanceEnableJMX – The ability to
manage the connections is exposed when you define a
loadBalanceConnectionGroup, but if you want
to manage this externally, enable JMX by setting this property
to true. This enables a JMX implementation,
which exposes the management and monitoring operations of a
connection group. Further, start your application with the
-Dcom.sun.management.jmxremote JVM flag.
You can then perform connect and perform operations using a
JMX client such as jconsole.
Once a connection has been made using the correct connection string options, a number of monitoring properties are available:
Current active host count.
Current active physical connection count.
Current active logical connection count.
Total logical connections created.
Total transaction count.
The following management operations can also be performed:
Add host.
Remove host.
The JMX interface,
com.mysql.jdbc.jmx.LoadBalanceConnectionGroupManagerMBean,
has the following methods:
int getActiveHostCount(String group);
int getTotalHostCount(String group);
long getTotalLogicalConnectionCount(String
group);
long getActiveLogicalConnectionCount(String
group);
long getActivePhysicalConnectionCount(String
group);
long getTotalPhysicalConnectionCount(String
group);
long getTotalTransactionCount(String
group);
void removeHost(String group, String host) throws
SQLException;
void stopNewConnectionsToHost(String group, String
host) throws SQLException;
void addHost(String group, String host, boolean
forExisting);
String getActiveHostsList(String group);
String getRegisteredConnectionGroups();
The getRegisteredConnectionGroups() method
returns the names of all connection groups defined in that class
loader.
You can test this setup with the following code:
public class Test {
private static String URL = "jdbc:mysql:loadbalance://" +
"localhost:3306,localhost:3310/test?" +
"loadBalanceConnectionGroup=first&loadBalanceEnableJMX=true";
public static void main(String[] args) throws Exception {
new Thread(new Repeater()).start();
new Thread(new Repeater()).start();
new Thread(new Repeater()).start();
}
static Connection getNewConnection() throws SQLException, ClassNotFoundException {
Class.forName("com.mysql.jdbc.Driver");
return DriverManager.getConnection(URL, "root", "");
}
static void executeSimpleTransaction(Connection c, int conn, int trans){
try {
c.setAutoCommit(false);
Statement s = c.createStatement();
s.executeQuery("SELECT SLEEP(1) /* Connection: " + conn + ", transaction: " + trans + " */");
c.commit();
} catch (SQLException e) {
e.printStackTrace();
}
}
public static class Repeater implements Runnable {
public void run() {
for(int i=0; i < 100; i++){
try {
Connection c = getNewConnection();
for(int j=0; j < 10; j++){
executeSimpleTransaction(c, i, j);
Thread.sleep(Math.round(100 * Math.random()));
}
c.close();
Thread.sleep(100);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}
After compiling, the application can be started with the
-Dcom.sun.management.jmxremote flag, to enable
remote management. jconsole can then be
started. The Test main class will be listed by
jconsole. Select this and click
. You can then navigate to the
com.mysql.jdbc.jmx.LoadBalanceConnectionGroupManager
bean. At this point, you can click on various operations and
examine the returned result.
If you now had an additional instance of MySQL running on port
3309, you could ensure that Connector/J starts using it by using
the addHost(), which is exposed in
jconsole. Note that these operations can be
performed dynamically without having to stop the application
running.
For further information on the combination of load balancing and failover, see Chapter 9, Load Balancing Failover Policies.
Connector/J provides a useful load-balancing implementation for
Cluster or multi-master deployments, as explained in
Chapter 8, Managing Load-Balanced Connections.
As of Connector/J 5.1.12, this same implementation is used for
balancing load between read-only slaves with
ReplicationDriver. When trying to balance
workload between multiple servers, the driver has to determine
when it is safe to swap servers, doing so in the middle of a
transaction, for example, could cause problems. It is important
not to lose state information. For this reason, Connector/J will
only try to pick a new server when one of the following happens:
At transaction boundaries (transactions are explicitly committed or rolled back).
A communication exception (SQL State starting with "08") is encountered.
When a SQLException matches conditions
defined by user, using the extension points defined by the
loadBalanceSQLStateFailover,
loadBalanceSQLExceptionSubclassFailover or
loadBalanceExceptionChecker properties.
The third condition revolves around three new properties
introduced with Connector/J 5.1.13. It allows you to control which
SQLExceptions trigger failover.
loadBalanceExceptionChecker - The
loadBalanceExceptionChecker property is
really the key. This takes a fully-qualified class name which
implements the new
com.mysql.jdbc.LoadBalanceExceptionChecker
interface. This interface is very simple, and you only need to
implement the following method:
public boolean shouldExceptionTriggerFailover(SQLException ex)
A SQLException is passed in, and a boolean
returned. A value of true triggers a
failover, false does not.
You can use this to implement your own custom logic. An example where this might be useful is when dealing with transient errors when using MySQL Cluster, where certain buffers may become overloaded. The following code snippet illustrates this:
public class NdbLoadBalanceExceptionChecker
extends StandardLoadBalanceExceptionChecker {
public boolean shouldExceptionTriggerFailover(SQLException ex) {
return super.shouldExceptionTriggerFailover(ex)
|| checkNdbException(ex);
}
private boolean checkNdbException(SQLException ex){
// Have to parse the message since most NDB errors
// are mapped to the same DEMC.
return (ex.getMessage().startsWith("Lock wait timeout exceeded") ||
(ex.getMessage().startsWith("Got temporary error")
&& ex.getMessage().endsWith("from NDB")));
}
}
The code above extends
com.mysql.jdbc.StandardLoadBalanceExceptionChecker,
which is the default implementation. There are a few
convenient shortcuts built into this, for those who want to
have some level of control using properties, without writing
Java code. This default implementation uses the two remaining
properties: loadBalanceSQLStateFailover and
loadBalanceSQLExceptionSubclassFailover.
loadBalanceSQLStateFailover - allows you to
define a comma-delimited list of SQLState
code prefixes, against which a SQLException
is compared. If the prefix matches, failover is triggered. So,
for example, the following would trigger a failover if a given
SQLException starts with "00", or is
"12345":
loadBalanceSQLStateFailover=00,12345
loadBalanceSQLExceptionSubclassFailover -
can be used in conjunction with
loadBalanceSQLStateFailover or on its own.
If you want certain subclasses of
SQLException to trigger failover, simply
provide a comma-delimited list of fully-qualified class or
interface names to check against. For example, if you want all
SQLTransientConnectionExceptions to trigger
failover, you would specify:
loadBalanceSQLExceptionSubclassFailover=java.sql.SQLTransientConnectionException
While the three fail-over conditions enumerated earlier suit most
situations, if auto-commit is enabled,
Connector/J never re-balances, and continues using the same
physical connection. This can be problematic, particularly when
load-balancing is being used to distribute read-only load across
multiple slaves. However, Connector/J can be configured to
re-balance after a certain number of statements are executed, when
auto-commit is enabled. This functionality is
dependent upon the following properties:
loadBalanceAutoCommitStatementThreshold –
defines the number of matching statements which will trigger
the driver to potentially swap physical server connections.
The default value, 0, retains the behavior that connections
with auto-commit enabled are never
balanced.
loadBalanceAutoCommitStatementRegex – the
regular expression against which statements must match. The
default value, blank, matches all statements. So, for example,
using the following properties will cause Connector/J to
re-balance after every third statement that contains the
string “test”:
loadBalanceAutoCommitStatementThreshold=3 loadBalanceAutoCommitStatementRegex=.*test.*
loadBalanceAutoCommitStatementRegex can
prove useful in a number of situations. Your application may
use temporary tables, server-side session state variables, or
connection state, where letting the driver arbitrarily swap
physical connections before processing is complete could cause
data loss or other problems. This allows you to identify a
trigger statement that is only executed when it is safe to
swap physical connections.
An interceptor is a software design pattern that provides a transparent way to extend or modify some aspect of a program, similar to a user exit. No recompiling is required. With Connector/J, the interceptors are enabled and disabled by updating the connection string to refer to different sets of interceptor classes that you instantiate.
The connection properties that control the interceptors are explained in Section 5.1, “Driver/Datasource Class Names, URL Syntax and Configuration Properties for Connector/J”:
connectionLifecycleInterceptors, where you
specify the fully qualified names of classes that implement
the
com.mysql.jdbc.ConnectionLifecycleInterceptor
interface. In these kinds of interceptor classes, you might
log events such as rollbacks, measure the time between
transaction start and end, or count events such as calls to
setAutoCommit().
exceptionInterceptors, where you specify
the fully qualified names of classes that implement the
com.mysql.jdbc.ExceptionInterceptor
interface. In these kinds of interceptor classes, you might
add extra diagnostic information to exceptions that can have
multiple causes or indicate a problem with server settings.
Because exceptionInterceptors classes are
only called when handling a SQLException
thrown from Connector/J code, they can be used even in
production deployments without substantial performance
overhead.
statementInterceptors, where you specify
the fully qualified names of classes that implement the
com.mysql.jdbc.StatementInterceptorV2
interface. In these kinds of interceptor classes, you might
change or augment the processing done by certain kinds of
statements, such as automatically checking for queried data in
a memcached server, rewriting slow queries,
logging information about statement execution, or route
requests to remote servers.
The following instructions are based on the instructions for Tomcat-5.x, available at http://tomcat.apache.org/tomcat-5.5-doc/jndi-datasource-examples-howto.html which is current at the time this document was written.
First, install the .jar file that comes with
Connector/J in $CATALINA_HOME/common/lib so
that it is available to all applications installed in the
container.
Next, configure the JNDI DataSource by adding a declaration
resource to $CATALINA_HOME/conf/server.xml in
the context that defines your web application:
<Context ....>
...
<Resource name="jdbc/MySQLDB"
auth="Container"
type="javax.sql.DataSource"/>
<ResourceParams name="jdbc/MySQLDB">
<parameter>
<name>factory</name>
<value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
</parameter>
<parameter>
<name>maxActive</name>
<value>10</value>
</parameter>
<parameter>
<name>maxIdle</name>
<value>5</value>
</parameter>
<parameter>
<name>validationQuery</name>
<value>SELECT 1</value>
</parameter>
<parameter>
<name>testOnBorrow</name>
<value>true</value>
</parameter>
<parameter>
<name>testWhileIdle</name>
<value>true</value>
</parameter>
<parameter>
<name>timeBetweenEvictionRunsMillis</name>
<value>10000</value>
</parameter>
<parameter>
<name>minEvictableIdleTimeMillis</name>
<value>60000</value>
</parameter>
<parameter>
<name>username</name>
<value>someuser</value>
</parameter>
<parameter>
<name>password</name>
<value>somepass</value>
</parameter>
<parameter>
<name>driverClassName</name>
<value>com.mysql.jdbc.Driver</value>
</parameter>
<parameter>
<name>url</name>
<value>jdbc:mysql://localhost:3306/test</value>
</parameter>
</ResourceParams>
</Context>
Note that Connector/J 5.1.3 introduced a facility whereby, rather
than use a validationQuery value of
SELECT 1, it is possible to use
validationQuery with a value set to /*
ping */. This sends a ping to the server which then
returns a fake result set. This is a lighter weight solution. It
also has the advantage that if using
ReplicationConnection or
LoadBalancedConnection type connections, the
ping will be sent across all active connections. The following XML
snippet illustrates how to select this option:
<parameter> <name>validationQuery</name> <value>/* ping */</value> </parameter>
Note that /* ping */ has to be specified
exactly.
In general, follow the installation instructions that come with your version of Tomcat, as the way you configure datasources in Tomcat changes from time to time, and if you use the wrong syntax in your XML file, you will most likely end up with an exception similar to the following:
Error: java.sql.SQLException: Cannot load JDBC driver class 'null ' SQL state: null
Note that the auto-loading of drivers having the
META-INF/service/java.sql.Driver class in
JDBC 4.0 causes an improper undeployment of the Connector/J driver
in Tomcat on Windows. Namely, the Connector/J jar remains locked.
This is an initialization problem that is not related to the
driver. The possible workarounds, if viable, are as follows: use
"antiResourceLocking=true" as a Tomcat Context
attribute, or remove the META-INF/ directory.
These instructions cover JBoss-4.x. To make the JDBC driver
classes available to the application server, copy the
.jar file that comes with Connector/J to the
lib directory for your server configuration
(which is usually called default). Then, in
the same configuration directory, in the subdirectory named
deploy, create a datasource configuration file that ends with
-ds.xml, which tells JBoss to deploy this file
as a JDBC Datasource. The file should have the following contents:
<datasources>
<local-tx-datasource>
<jndi-name>MySQLDB</jndi-name>
<connection-url>jdbc:mysql://localhost:3306/dbname</connection-url>
<driver-class>com.mysql.jdbc.Driver</driver-class>
<user-name>user</user-name>
<password>pass</password>
<min-pool-size>5</min-pool-size>
<max-pool-size>20</max-pool-size>
<idle-timeout-minutes>5</idle-timeout-minutes>
<exception-sorter-class-name>
com.mysql.jdbc.integration.jboss.ExtendedMysqlExceptionSorter
</exception-sorter-class-name>
<valid-connection-checker-class-name>
com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker
</valid-connection-checker-class-name>
</local-tx-datasource>
</datasources> Table of Contents
The Spring Framework is a Java-based application framework designed for assisting in application design by providing a way to configure components. The technique used by Spring is a well known design pattern called Dependency Injection (see Inversion of Control Containers and the Dependency Injection pattern). This article will focus on Java-oriented access to MySQL databases with Spring 2.0. For those wondering, there is a .NET port of Spring appropriately named Spring.NET.
Spring is not only a system for configuring components, but also includes support for aspect oriented programming (AOP). This is one of the main benefits and the foundation for Spring's resource and transaction management. Spring also provides utilities for integrating resource management with JDBC and Hibernate.
For the examples in this section the MySQL world sample database will be used. The first task is to set up a MySQL data source through Spring. Components within Spring use the “bean” terminology. For example, to configure a connection to a MySQL server supporting the world sample database, you might use:
<util:map id="dbProps">
<entry key="db.driver" value="com.mysql.jdbc.Driver"/>
<entry key="db.jdbcurl" value="jdbc:mysql://localhost/world"/>
<entry key="db.username" value="myuser"/>
<entry key="db.password" value="mypass"/>
</util:map>
In the above example, we are assigning values to properties that will be used in the configuration. For the datasource configuration:
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${db.driver}"/>
<property name="url" value="${db.jdbcurl}"/>
<property name="username" value="${db.username}"/>
<property name="password" value="${db.password}"/>
</bean>
The placeholders are used to provide values for properties of this bean. This means that you can specify all the properties of the configuration in one place instead of entering the values for each property on each bean. We do, however, need one more bean to pull this all together. The last bean is responsible for actually replacing the placeholders with the property values.
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="properties" ref="dbProps"/>
</bean>
Now that we have our MySQL data source configured and ready to go, we write some Java code to access it. The example below will retrieve three random cities and their corresponding country using the data source we configured with Spring.
// Create a new application context. this processes the Spring config
ApplicationContext ctx =
new ClassPathXmlApplicationContext("ex1appContext.xml");
// Retrieve the data source from the application context
DataSource ds = (DataSource) ctx.getBean("dataSource");
// Open a database connection using Spring's DataSourceUtils
Connection c = DataSourceUtils.getConnection(ds);
try {
// retrieve a list of three random cities
PreparedStatement ps = c.prepareStatement(
"select City.Name as 'City', Country.Name as 'Country' " +
"from City inner join Country on City.CountryCode = Country.Code " +
"order by rand() limit 3");
ResultSet rs = ps.executeQuery();
while(rs.next()) {
String city = rs.getString("City");
String country = rs.getString("Country");
System.out.printf("The city %s is in %s%n", city, country);
}
} catch (SQLException ex) {
// something has failed and we print a stack trace to analyse the error
ex.printStackTrace();
// ignore failure closing connection
try { c.close(); } catch (SQLException e) { }
} finally {
// properly release our connection
DataSourceUtils.releaseConnection(c, ds);
}This is very similar to normal JDBC access to MySQL with the main difference being that we are using DataSourceUtils instead of the DriverManager to create the connection.
While it may seem like a small difference, the implications are somewhat far reaching. Spring manages this resource in a way similar to a container managed data source in a J2EE application server. When a connection is opened, it can be subsequently accessed in other parts of the code if it is synchronized with a transaction. This makes it possible to treat different parts of your application as transactional instead of passing around a database connection.
Spring makes extensive use of the Template method design pattern
(see
Template
Method Pattern). Our immediate focus will be on the
JdbcTemplate and related classes,
specifically NamedParameterJdbcTemplate. The
template classes handle obtaining and releasing a connection for
data access when one is needed.
The next example shows how to use
NamedParameterJdbcTemplate inside of a DAO
(Data Access Object) class to retrieve a random city given a
country code.
public class Ex2JdbcDao {
/**
* Data source reference which will be provided by Spring.
*/
private DataSource dataSource;
/**
* Our query to find a random city given a country code. Notice
* the ":country" parameter toward the end. This is called a
* named parameter.
*/
private String queryString = "select Name from City " +
"where CountryCode = :country order by rand() limit 1";
/**
* Retrieve a random city using Spring JDBC access classes.
*/
public String getRandomCityByCountryCode(String cntryCode) {
// A template that permits using queries with named parameters
NamedParameterJdbcTemplate template =
new NamedParameterJdbcTemplate(dataSource);
// A java.util.Map is used to provide values for the parameters
Map params = new HashMap();
params.put("country", cntryCode);
// We query for an Object and specify what class we are expecting
return (String)template.queryForObject(queryString, params, String.class);
}
/**
* A JavaBean setter-style method to allow Spring to inject the data source.
* @param dataSource
*/
public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
}
}
The focus in the above code is on the
getRandomCityByCountryCode() method. We
pass a country code and use the
NamedParameterJdbcTemplate to query for a
city. The country code is placed in a Map with the key
"country", which is the parameter is named in the SQL query.
To access this code, you need to configure it with Spring by providing a reference to the data source.
<bean id="dao" class="code.Ex2JdbcDao">
<property name="dataSource" ref="dataSource"/>
</bean>
At this point, we can just grab a reference to the DAO from
Spring and call
getRandomCityByCountryCode().
// Create the application context
ApplicationContext ctx =
new ClassPathXmlApplicationContext("ex2appContext.xml");
// Obtain a reference to our DAO
Ex2JdbcDao dao = (Ex2JdbcDao) ctx.getBean("dao");
String countryCode = "USA";
// Find a few random cities in the US
for(int i = 0; i < 4; ++i)
System.out.printf("A random city in %s is %s%n", countryCode,
dao.getRandomCityByCountryCode(countryCode));
This example shows how to use Spring's JDBC classes to
completely abstract away the use of traditional JDBC classes
including Connection and
PreparedStatement.
You might be wondering how we can add transactions into our code if we do not deal directly with the JDBC classes. Spring provides a transaction management package that not only replaces JDBC transaction management, but also enables declarative transaction management (configuration instead of code).
To use transactional database access, we will need to change the storage engine of the tables in the world database. The downloaded script explicitly creates MyISAM tables which do not support transactional semantics. The InnoDB storage engine does support transactions and this is what we will be using. We can change the storage engine with the following statements.
ALTER TABLE City ENGINE=InnoDB; ALTER TABLE Country ENGINE=InnoDB; ALTER TABLE CountryLanguage ENGINE=InnoDB;
A good programming practice emphasized by Spring is separating interfaces and implementations. What this means is that we can create a Java interface and only use the operations on this interface without any internal knowledge of what the actual implementation is. We will let Spring manage the implementation and with this it will manage the transactions for our implementation.
First you create a simple interface:
public interface Ex3Dao {
Integer createCity(String name, String countryCode,
String district, Integer population);
}This interface contains one method that will create a new city record in the database and return the id of the new record. Next you need to create an implementation of this interface.
public class Ex3DaoImpl implements Ex3Dao {
protected DataSource dataSource;
protected SqlUpdate updateQuery;
protected SqlFunction idQuery;
public Integer createCity(String name, String countryCode,
String district, Integer population) {
updateQuery.update(new Object[] { name, countryCode,
district, population });
return getLastId();
}
protected Integer getLastId() {
return idQuery.run();
}
}You can see that we only operate on abstract query objects here and do not deal directly with the JDBC API. Also, this is the complete implementation. All of our transaction management will be dealt with in the configuration. To get the configuration started, we need to create the DAO.
<bean id="dao" class="code.Ex3DaoImpl">
<property name="dataSource" ref="dataSource"/>
<property name="updateQuery">...</property>
<property name="idQuery">...</property>
</bean>
Now you need to set up the transaction configuration. The first
thing you must do is create transaction manager to manage the
data source and a specification of what transaction properties
are required for the dao methods.
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="*"/>
</tx:attributes>
</tx:advice>
The preceding code creates a transaction manager that handles
transactions for the data source provided to it. The
txAdvice uses this transaction manager and
the attributes specify to create a transaction for all methods.
Finally you need to apply this advice with an AOP pointcut.
<aop:config>
<aop:pointcut id="daoMethods"
expression="execution(* code.Ex3Dao.*(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="daoMethods"/>
</aop:config>
This basically says that all methods called on the
Ex3Dao interface will be wrapped in a
transaction. To make use of this, you only have to retrieve the
dao from the application context and call a
method on the dao instance.
Ex3Dao dao = (Ex3Dao) ctx.getBean("dao");
Integer id = dao.createCity(name, countryCode, district, pop);We can verify from this that there is no transaction management happening in our Java code and it is all configured with Spring. This is a very powerful notion and regarded as one of the most beneficial features of Spring.
In many situations, such as web applications, there will be a
large number of small database transactions. When this is the
case, it usually makes sense to create a pool of database
connections available for web requests as needed. Although MySQL
does not spawn an extra process when a connection is made, there
is still a small amount of overhead to create and set up the
connection. Pooling of connections also alleviates problems such
as collecting large amounts of sockets in the
TIME_WAIT state.
Setting up pooling of MySQL connections with Spring is as simple
as changing the data source configuration in the application
context. There are a number of configurations that we can use.
The first example is based on the
Jakarta
Commons DBCP library. The example below replaces the
source configuration that was based on
DriverManagerDataSource with DBCP's
BasicDataSource.
<bean id="dataSource" destroy-method="close"
class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="${db.driver}"/>
<property name="url" value="${db.jdbcurl}"/>
<property name="username" value="${db.username}"/>
<property name="password" value="${db.password}"/>
<property name="initialSize" value="3"/>
</bean>
The configuration of the two solutions is very similar. The
difference is that DBCP will pool connections to the database
instead of creating a new connection every time one is
requested. We have also set a parameter here called
initialSize. This tells DBCP that we want
three connections in the pool when it is created.
Another way to configure connection pooling is to configure a
data source in our J2EE application server. Using JBoss as an
example, you can set up the MySQL connection pool by creating a
file called mysql-local-ds.xml and placing
it in the server/default/deploy directory in JBoss. Once we have
this setup, we can use JNDI to look it up. With Spring, this
lookup is very simple. The data source configuration looks like
this.
<jee:jndi-lookup id="dataSource" jndi-name="java:MySQL_DS"/>
Table of Contents
This section explains how to use MySQL Connector/J with Glassfish ™ Server Open Source Edition 3.0.1. Glassfish can be downloaded from the Glassfish website.
Once Glassfish is installed you will need to make sure it can
access MySQL Connector/J. To do this copy the MySQL Connector/J JAR file to the directory
GLASSFISH_INSTALL/glassfish/libmysql-connector-java-5.1.12-bin.jar to
C:\glassfishv3\glassfish\lib. Restart the
Glassfish Application Server.
You are now ready to create JDBC Connection Pools and JDBC Resources.
Creating a Connection Pool
In the Glassfish Administration Console, using the navigation tree navigate to Resources, JDBC, Connection Pools.
In the JDBC Connection Pools frame click . You will enter a two step wizard.
In the Name field under General
Settings enter the name for the connection pool,
for example enter MySQLConnPool.
In the Resource Type field, select
javax.sql.DataSource from the drop-down
listbox.
In the Database Vendor field, select
MySQL from the drop-down listbox. Click
to go to the next page of the
wizard.
You can accept the default settings for General Settings, Pool Settings and Transactions for this example. Scroll down to Additional Properties.
In Additional Properties you will need to ensure the following properties are set:
ServerName - The server
to connect to. For local testing this will be
localhost.
User - The user name with which to connect to MySQL.
Password - The corresponding password for the user.
DatabaseName - The
database to connect to, for example the sample MySQL
database World.
Click to exit the wizard. You will be taken to the JDBC Connection Pools page where all current connection pools, including the one you just created, will be displayed.
In the JDBC Connection Pools frame click on the connection pool you just created. Here you can review and edit information about the connection pool.
To test your connection pool click the button at the top of the frame. A message will be displayed confirming correct operation or otherwise. If an error message is received recheck the previous steps, and ensure that MySQL Connector/J has been correctly copied into the previously specified location.
Now that you have created a connection pool you will also need to create a JDBC Resource (data source) for use by your application.
Creating a JDBC Resource
Your Java application will usually reference a data source object to establish a connection with the database. This needs to be created first using the following procedure.
Using the navigation tree in the Glassfish Administration Console, navigate to Resources, JDBC, JDBC Resources. A list of resources will be displayed in the JDBC Resources frame.
Click . The New JDBC Resource frame will be displayed.
In the JNDI Name field, enter the JNDI
name that will be used to access this resource, for example
enter jdbc/MySQLDataSource.
In the Pool Name field, select a connection pool you want this resource to use from the drop-down listbox.
Optionally, you can enter a description into the Description field.
Additional properties can be added if required.
Click to create the new JDBC resource. The JDBC Resources frame will list all available JDBC Resources.
This section shows how to deploy a simple JSP application on Glassfish, that connects to a MySQL database.
This example assumes you have already set up a suitable
Connection Pool and JDBC Resource, as explained in the preceding
sections. It is also assumed you have a sample database
installed, such as world.
The main application code, index.jsp is
presented here:
<%@ page import="java.sql.*, javax.sql.*, java.io.*, javax.naming.*" %>
<html>
<head><title>Hello world from JSP</title></head>
<body>
<%
InitialContext ctx;
DataSource ds;
Connection conn;
Statement stmt;
ResultSet rs;
try {
ctx = new InitialContext();
ds = (DataSource) ctx.lookup("java:comp/env/jdbc/MySQLDataSource");
//ds = (DataSource) ctx.lookup("jdbc/MySQLDataSource");
conn = ds.getConnection();
stmt = conn.createStatement();
rs = stmt.executeQuery("SELECT * FROM Country");
while(rs.next()) {
%>
<h3>Name: <%= rs.getString("Name") %></h3>
<h3>Population: <%= rs.getString("Population") %></h3>
<%
}
}
catch (SQLException se) {
%>
<%= se.getMessage() %>
<%
}
catch (NamingException ne) {
%>
<%= ne.getMessage() %>
<%
}
%>
</body>
</html>
In addition two XML files are required:
web.xml, and
sun-web.xml. There may be other files
present, such as classes and images. These files are organized
into the directory structure as follows:
index.jsp WEB-INF | - web.xml - sun-web.xml
The code for web.xml is:
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>HelloWebApp</display-name>
<distributable/>
<resource-ref>
<res-ref-name>jdbc/MySQLDataSource</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
</web-app>
The code for sun-web.xml is:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sun-web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Application Server 8.1 Servlet 2.4//EN" "http://www.sun.com/software/appserver/dtds/sun-web-app_2_4-1.dtd">
<sun-web-app>
<context-root>HelloWebApp</context-root>
<resource-ref>
<res-ref-name>jdbc/MySQLDataSource</res-ref-name>
<jndi-name>jdbc/MySQLDataSource</jndi-name>
</resource-ref>
</sun-web-app>
These XML files illustrate a very important aspect of running
JDBC applications on Glassfish. On Glassfish it is important to
map the string specified for a JDBC resource to its JNDI name,
as set up in the Glassfish administration console. In this
example, the JNDI name for the JDBC resource, as specified in
the Glassfish Administration console when creating the JDBC
Resource, was jdbc/MySQLDataSource. This must
be mapped to the name given in the application. In this example
the name specified in the application,
jdbc/MySQLDataSource, and the JNDI name,
happen to be the same, but this does not necessarily have to be
the case. Note that the XML element <res-ref-name> is used
to specify the name as used in the application source code, and
this is mapped to the JNDI name specified using the
<jndi-name> element, in the file
sun-web.xml. The resource also has to be
created in the web.xml file, although the
mapping of the resource to a JNDI name takes place in the
sun-web.xml file.
If you do not have this mapping set up correctly in the XML files you will not be able to lookup the data source using a JNDI lookup string such as:
ds = (DataSource) ctx.lookup("java:comp/env/jdbc/MySQLDataSource");You will still be able to access the data source directly using:
ds = (DataSource) ctx.lookup("jdbc/MySQLDataSource");With the source files in place, in the correct directory structure, you are ready to deploy the application:
In the navigation tree, navigate to Applications - the Applications frame will be displayed. Click .
You can now deploy an application packaged into a single WAR file from a remote client, or you can choose a packaged file or directory that is locally accessible to the server. If you are simply testing an application locally you can simply point Glassfish at the directory that contains your application, without needing to package the application into a WAR file.
Now select the application type from the
Type drop-down listbox, which in this
example is Web application.
Click OK.
Now, when you navigate to the Applications
frame, you will have the option to Launch,
Redeploy, or Restart
your application. You can test your application by clicking
Launch. The application will connection to
the MySQL database and display the Name and Population of
countries in the Country table.
This section describes a simple servlet that can be used in the
Glassfish environment to access a MySQL database. As with the
previous section, this example assumes the sample database
world is installed.
The project is set up with the following directory structure:
index.html
WEB-INF
|
- web.xml
- sun-web.xml
- classes
|
- HelloWebServlet.java
- HelloWebServlet.class
The code for the servlet, located in
HelloWebServlet.java, is as follows:
import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;
import java.sql.*;
import javax.sql.*;
import javax.naming.*;
public class HelloWebServlet extends HttpServlet {
InitialContext ctx = null;
DataSource ds = null;
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "SELECT Name, Population FROM Country WHERE Name=?";
public void init () throws ServletException {
try {
ctx = new InitialContext();
ds = (DataSource) ctx.lookup("java:comp/env/jdbc/MySQLDataSource");
conn = ds.getConnection();
ps = conn.prepareStatement(sql);
}
catch (SQLException se) {
System.out.println("SQLException: "+se.getMessage());
}
catch (NamingException ne) {
System.out.println("NamingException: "+ne.getMessage());
}
}
public void destroy () {
try {
if (rs != null)
rs.close();
if (ps != null)
ps.close();
if (conn != null)
conn.close();
if (ctx != null)
ctx.close();
}
catch (SQLException se) {
System.out.println("SQLException: "+se.getMessage());
}
catch (NamingException ne) {
System.out.println("NamingException: "+ne.getMessage());
}
}
public void doPost(HttpServletRequest req, HttpServletResponse resp){
try {
String country_name = req.getParameter("country_name");
resp.setContentType("text/html");
PrintWriter writer = resp.getWriter();
writer.println("<html><body>");
writer.println("<p>Country: "+country_name+"</p>");
ps.setString(1, country_name);
rs = ps.executeQuery();
if (!rs.next()){
writer.println("<p>Country does not exist!</p>");
}
else {
rs.beforeFirst();
while(rs.next()) {
writer.println("<p>Name: "+rs.getString("Name")+"</p>");
writer.println("<p>Population: "+rs.getString("Population")+"</p>");
}
}
writer.println("</body></html>");
writer.close();
}
catch (Exception e) {
e.printStackTrace();
}
}
public void doGet(HttpServletRequest req, HttpServletResponse resp){
try {
resp.setContentType("text/html");
PrintWriter writer = resp.getWriter();
writer.println("<html><body>");
writer.println("<p>Hello from servlet doGet()</p>");
writer.println("</body></html>");
writer.close();
}
catch (Exception e) {
e.printStackTrace();
}
}
}
In the preceding code a basic doGet() method
is implemented, but is not used in the example. The code to
establish the connection with the database is as shown in the
previous example,
Section 14.1, “A Simple JSP Application with Glassfish, Connector/J and MySQL”,
and is most conveniently located in the servlet
init() method. The corresponding freeing of
resources is located in the destroy method. The main
functionality of the servlet is located in the
doPost() method. If the user enters nto the
input form a country name that can be located in the database,
the population of the country is returned. The code is invoked
using a POST action associated with the input form. The form is
defined in the file index.html:
<html>
<head><title>HelloWebServlet</title></head>
<body>
<h1>HelloWebServlet</h1>
<p>Please enter country name:</p>
<form action="HelloWebServlet" method="POST">
<input type="text" name="country_name" length="50" />
<input type="submit" value="Submit" />
</form>
</body>
</html>
The XML files web.xml and
sun-web.xml are as for the example in the
preceding section,
Section 14.1, “A Simple JSP Application with Glassfish, Connector/J and MySQL”,
no additional changes are required.
Whe compiling the Java source code, you will need to specify the
path to the file javaee.jar. On Windows,
this can be done as follows:
shell> javac -classpath c:\glassfishv3\glassfish\lib\javaee.jar HelloWebServlet.java
Once the code is correctly located within its directory structure, and compiled, the application can be deployed in Glassfish. This is done in exactly the same way as described in the preceding section, Section 14.1, “A Simple JSP Application with Glassfish, Connector/J and MySQL”.
Once deployed the application can be launched from within the Glassfish Administration Console. Enter a country name such as “England”, and the application will return “Country does not exist!”. Enter “France”, and the application will return a population of 59225700.
This section explains the symptoms and resolutions for the most commonly encountered issues with applications using MySQL Connector/J.
Questions
15.1: When I try to connect to the database with MySQL Connector/J, I get the following exception:
SQLException: Server configuration denies access to data source SQLState: 08001 VendorError: 0
What is going on? I can connect just fine with the MySQL command-line client.
15.2: My application throws an SQLException 'No Suitable Driver'. Why is this happening?
15.3: I'm trying to use MySQL Connector/J in an applet or application and I get an exception similar to:
SQLException: Cannot connect to MySQL server on host:3306. Is there a MySQL server running on the machine/port you are trying to connect to? (java.security.AccessControlException) SQLState: 08S01 VendorError: 0
15.4: I have a servlet/application that works fine for a day, and then stops working overnight
15.5: I'm trying to use JDBC 2.0 updatable result sets, and I get an exception saying my result set is not updatable.
15.6: I cannot connect to the MySQL server using Connector/J, and I'm sure the connection parameters are correct.
15.7: I am trying to connect to my MySQL server within my application, but I get the following error and stack trace:
java.net.SocketException MESSAGE: Software caused connection abort: recv failed STACKTRACE: java.net.SocketException: Software caused connection abort: recv failed at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.read(Unknown Source) at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1392) at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:1414) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:625) at com.mysql.jdbc.Connection.createNewIO(Connection.java:1926) at com.mysql.jdbc.Connection.<init>(Connection.java:452) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:411)
15.8: My application is deployed through JBoss and I am using transactions to handle the statements on the MySQL database. Under heavy loads I am getting a error and stack trace, but these only occur after a fixed period of heavy activity.
15.9:
When using gcj an
java.io.CharConversionException is raised
when working with certain character sequences.
15.10:
Updating a table that contains a primary key that is either
FLOAT or compound primary key
that uses FLOAT fails to
update the table and raises an exception.
15.11:
You get an
ER_NET_PACKET_TOO_LARGE
exception, even though the binary blob size you want to
insert using JDBC is safely below the
max_allowed_packet size.
15.12: What should you do if you receive error messages similar to the following: “Communications link failure – Last packet sent to the server was X ms ago”?
15.13:
Why does Connector/J not reconnect to MySQL and re-issue the
statement after a communication failure, instead of throwing
an Exception, even though I use the
autoReconnect connection string option?
15.14: How can I use 3-byte UTF8 with Connector/J?
15.15:
How can I use 4-byte UTF8, utf8mb4 with
Connector/J?
15.16:
Using useServerPrepStmts=false and
certain character encodings can lead to corruption when
inserting BLOBs. How can this be avoided?
Questions and Answers
15.1: When I try to connect to the database with MySQL Connector/J, I get the following exception:
SQLException: Server configuration denies access to data source SQLState: 08001 VendorError: 0
What is going on? I can connect just fine with the MySQL command-line client.
MySQL Connector/J must use TCP/IP sockets to connect to MySQL, as Java does not support Unix Domain Sockets. Therefore, when MySQL Connector/J connects to MySQL, the security manager in MySQL server will use its grant tables to determine whether the connection is permitted.
You must add the necessary security credentials to the MySQL
server for this to happen, using the
GRANT statement to your MySQL
Server. See GRANT Syntax, for more information.
Testing your connectivity with the
mysql command-line client will not work
unless you add the "host" flag, and use something other
than localhost for the host. The
mysql command-line client will use Unix
domain sockets if you use the special host name
localhost. If you are testing
connectivity to localhost, use
127.0.0.1 as the host name instead.
Changing privileges and permissions improperly in MySQL can potentially cause your server installation to not have optimal security properties.
15.2: My application throws an SQLException 'No Suitable Driver'. Why is this happening?
There are three possible causes for this error:
The Connector/J driver is not in your
CLASSPATH, see
Chapter 3, Connector/J Installation.
The format of your connection URL is incorrect, or you are referencing the wrong JDBC driver.
When using DriverManager, the
jdbc.drivers system property has not
been populated with the location of the Connector/J
driver.
15.3: I'm trying to use MySQL Connector/J in an applet or application and I get an exception similar to:
SQLException: Cannot connect to MySQL server on host:3306. Is there a MySQL server running on the machine/port you are trying to connect to? (java.security.AccessControlException) SQLState: 08S01 VendorError: 0
Either you're running an Applet, your MySQL server has been installed with the "skip-networking" option set, or your MySQL server has a firewall sitting in front of it.
Applets can only make network connections back to the machine that runs the web server that served the .class files for the applet. This means that MySQL must run on the same machine (or you must have some sort of port re-direction) for this to work. This also means that you will not be able to test applets from your local file system, you must always deploy them to a web server.
MySQL Connector/J can only communicate with MySQL using TCP/IP, as Java does not support Unix domain sockets. TCP/IP communication with MySQL might be affected if MySQL was started with the "skip-networking" flag, or if it is firewalled.
If MySQL has been started with the "skip-networking" option
set (the Debian Linux package of MySQL server does this for
example), you need to comment it out in the file
/etc/mysql/my.cnf or /etc/my.cnf. Of course your my.cnf file
might also exist in the data directory
of your MySQL server, or anywhere else (depending on how
MySQL was compiled for your system). Binaries created by us
always look in /etc/my.cnf and [datadir]/my.cnf. If your
MySQL server has been firewalled, you will need to have the
firewall configured to allow TCP/IP connections from the
host where your Java code is running to the MySQL server on
the port that MySQL is listening to (by default, 3306).
15.4: I have a servlet/application that works fine for a day, and then stops working overnight
MySQL closes connections after 8 hours of inactivity. You either need to use a connection pool that handles stale connections or use the "autoReconnect" parameter (see Section 5.1, “Driver/Datasource Class Names, URL Syntax and Configuration Properties for Connector/J”).
Also, catch SQLExceptions in your application and deal with
them, rather than propagating them all the way until your
application exits. This is just good programming practice.
MySQL Connector/J will set the SQLState (see
java.sql.SQLException.getSQLState() in
your API docs) to "08S01" when it encounters
network-connectivity issues during the processing of a
query. Attempt to reconnect to MySQL at this point.
The following (simplistic) example shows what code that can handle these exceptions might look like:
Example 15.1. Connector/J: Example of transaction with retry logic
public void doBusinessOp() throws SQLException {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
//
// How many times do you want to retry the transaction
// (or at least _getting_ a connection)?
//
int retryCount = 5;
boolean transactionCompleted = false;
do {
try {
conn = getConnection(); // assume getting this from a
// javax.sql.DataSource, or the
// java.sql.DriverManager
conn.setAutoCommit(false);
//
// Okay, at this point, the 'retry-ability' of the
// transaction really depends on your application logic,
// whether or not you're using autocommit (in this case
// not), and whether you're using transactional storage
// engines
//
// For this example, we'll assume that it's _not_ safe
// to retry the entire transaction, so we set retry
// count to 0 at this point
//
// If you were using exclusively transaction-safe tables,
// or your application could recover from a connection going
// bad in the middle of an operation, then you would not
// touch 'retryCount' here, and just let the loop repeat
// until retryCount == 0.
//
retryCount = 0;
stmt = conn.createStatement();
String query = "SELECT foo FROM bar ORDER BY baz";
rs = stmt.executeQuery(query);
while (rs.next()) {
}
rs.close();
rs = null;
stmt.close();
stmt = null;
conn.commit();
conn.close();
conn = null;
transactionCompleted = true;
} catch (SQLException sqlEx) {
//
// The two SQL states that are 'retry-able' are 08S01
// for a communications error, and 40001 for deadlock.
//
// Only retry if the error was due to a stale connection,
// communications problem or deadlock
//
String sqlState = sqlEx.getSQLState();
if ("08S01".equals(sqlState) || "40001".equals(sqlState)) {
retryCount -= 1;
} else {
retryCount = 0;
}
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException sqlEx) {
// You'd probably want to log this...
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException sqlEx) {
// You'd probably want to log this as well...
}
}
if (conn != null) {
try {
//
// If we got here, and conn is not null, the
// transaction should be rolled back, as not
// all work has been done
try {
conn.rollback();
} finally {
conn.close();
}
} catch (SQLException sqlEx) {
//
// If we got an exception here, something
// pretty serious is going on, so we better
// pass it up the stack, rather than just
// logging it...
throw sqlEx;
}
}
}
} while (!transactionCompleted && (retryCount > 0));
}
Use of the autoReconnect option is not
recommended because there is no safe method of
reconnecting to the MySQL server without risking some
corruption of the connection state or database state
information. Instead, use a connection pool, which will
enable your application to connect to the MySQL server
using an available connection from the pool. The
autoReconnect facility is deprecated, and
may be removed in a future release.
15.5: I'm trying to use JDBC 2.0 updatable result sets, and I get an exception saying my result set is not updatable.
Because MySQL does not have row identifiers, MySQL Connector/J can only update result sets that have come from queries on tables that have at least one primary key, the query must select every primary key and the query can only span one table (that is, no joins). This is outlined in the JDBC specification.
Note that this issue only occurs when using updatable result
sets, and is caused because Connector/J is unable to
guarantee that it can identify the correct rows within the
result set to be updated without having a unique reference
to each row. There is no requirement to have a unique field
on a table if you are using
UPDATE or
DELETE statements on a table
where you can individually specify the criteria to be
matched using a WHERE clause.
15.6: I cannot connect to the MySQL server using Connector/J, and I'm sure the connection parameters are correct.
Make sure that the
skip-networking option has
not been enabled on your server. Connector/J must be able to
communicate with your server over TCP/IP, named sockets are
not supported. Also ensure that you are not filtering
connections through a Firewall or other network security
system. For more information, see
Can't connect to [local] MySQL server.
15.7: I am trying to connect to my MySQL server within my application, but I get the following error and stack trace:
java.net.SocketException MESSAGE: Software caused connection abort: recv failed STACKTRACE: java.net.SocketException: Software caused connection abort: recv failed at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.read(Unknown Source) at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1392) at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:1414) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:625) at com.mysql.jdbc.Connection.createNewIO(Connection.java:1926) at com.mysql.jdbc.Connection.<init>(Connection.java:452) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:411)
The error probably indicates that you are using a older version of the Connector/J JDBC driver (2.0.14 or 3.0.x) and you are trying to connect to a MySQL server with version 4.1x or newer. The older drivers are not compatible with 4.1 or newer of MySQL as they do not support the newer authentication mechanisms.
It is likely that the older version of the Connector/J
driver exists within your application directory or your
CLASSPATH includes the older Connector/J
package.
15.8: My application is deployed through JBoss and I am using transactions to handle the statements on the MySQL database. Under heavy loads I am getting a error and stack trace, but these only occur after a fixed period of heavy activity.
This is a JBoss, not Connector/J, issue and is connected to the use of transactions. Under heavy loads the time taken for transactions to complete can increase, and the error is caused because you have exceeded the predefined timeout.
You can increase the timeout value by setting the
TransactionTimeout attribute to the
TransactionManagerService within the
/conf/jboss-service.xml file
(pre-4.0.3) or /deploy/jta-service.xml
for JBoss 4.0.3 or later. See
TransactionTimeoute
within the JBoss wiki for more information.
15.9:
When using gcj an
java.io.CharConversionException is raised
when working with certain character sequences.
This is a known issue with gcj which
raises an exception when it reaches an unknown character or
one it cannot convert. Add
useJvmCharsetConverters=true to your
connection string to force character conversion outside of
the gcj libraries, or try a different
JDK.
15.10:
Updating a table that contains a primary key that is either
FLOAT or compound primary key
that uses FLOAT fails to
update the table and raises an exception.
Connector/J adds conditions to the WHERE
clause during an UPDATE to
check the old values of the primary key. If there is no
match then Connector/J considers this a failure condition
and raises an exception.
The problem is that rounding differences between supplied values and the values stored in the database may mean that the values never match, and hence the update fails. The issue will affect all queries, not just those from Connector/J.
To prevent this issue, use a primary key that does not use
FLOAT. If you have to use a
floating point column in your primary key use
DOUBLE or
DECIMAL types in place of
FLOAT.
15.11:
You get an
ER_NET_PACKET_TOO_LARGE
exception, even though the binary blob size you want to
insert using JDBC is safely below the
max_allowed_packet size.
This is because the hexEscapeBlock()
method in
com.mysql.jdbc.PreparedStatement.streamToBytes()
may almost double the size of your data.
15.12: What should you do if you receive error messages similar to the following: “Communications link failure – Last packet sent to the server was X ms ago”?
Generally speaking, this error suggests that the network connection has been closed. There can be several root causes:
Firewalls or routers may clamp down on idle connections (the MySQL client/server protocol does not ping).
The MySQL Server may be closing idle connections which
exceed the wait_timeout or
interactive_timeout threshold.
To help troubleshoot these issues, the following tips can be used. If a recent (5.1.13+) version of Connector/J is used, you will see an improved level of information compared to earlier versions. Older versions simply display the last time a packet was sent to the server, which is frequently 0 ms ago. This is of limited use, as it may be that a packet was just sent, while a packet from the server has not been received for several hours. Knowing the period of time since Connector/J last received a packet from the server is useful information, so if this is not displayed in your exception message, it is recommended that you update Connector/J.
Further, if the time a packet was last sent/received exceeds
the wait_timeout or
interactive_timeout threshold, this is
noted in the exception message.
Although network connections can be volatile, the following can be helpful in avoiding problems:
Ensure connections are valid when used from the
connection pool. Use a query that starts with
/* ping */ to execute a lightweight
ping instead of full query. Note, the syntax of the ping
needs to be exactly as specified here.
Minimize the duration a connection object is left idle while other application logic is executed.
Explicitly validate the connection before using it if the connection has been left idle for an extended period of time.
Ensure that wait_timeout and
interactive_timeout are set
sufficiently high.
Ensure that tcpKeepalive is enabled.
Ensure that any configurable firewall or router timeout settings allow for the maximum expected connection idle time.
Do not expect to be able to reuse a connection without problems, if it has being lying idle for a period. If a connection is to be reused after being idle for any length of time, ensure that you explicitly test it before reusing it.
15.13:
Why does Connector/J not reconnect to MySQL and re-issue the
statement after a communication failure, instead of throwing
an Exception, even though I use the
autoReconnect connection string option?
There are several reasons for this. The first is transactional integrity. The MySQL Reference Manual states that “there is no safe method of reconnecting to the MySQL server without risking some corruption of the connection state or database state information”. Consider the following series of statements for example:
conn.createStatement().execute( "UPDATE checking_account SET balance = balance - 1000.00 WHERE customer='Smith'"); conn.createStatement().execute( "UPDATE savings_account SET balance = balance + 1000.00 WHERE customer='Smith'"); conn.commit();
Consider the case where the connection to the server fails
after the UPDATE to
checking_account. If no exception is
thrown, and the application never learns about the problem,
it will continue executing. However, the server did not
commit the first transaction in this case, so that will get
rolled back. But execution continues with the next
transaction, and increases the
savings_account balance by 1000. The
application did not receive an exception, so it continued
regardless, eventually committing the second transaction, as
the commit only applies to the changes made in the new
connection. Rather than a transfer taking place, a deposit
was made in this example.
Note that running with auto-commit
enabled does not solve this problem. When Connector/J
encounters a communication problem, there is no means to
determine whether the server processed the currently
executing statement or not. The following theoretical states
are equally possible:
The server never received the statement, and therefore no related processing occurred on the server.
The server received the statement, executed it in full, but the response was not received by the client.
If you are running with auto-commit
enabled, it is not possible to guarantee the state of data
on the server when a communication exception is encountered.
The statement may have reached the server, or it may not.
All you know is that communication failed at some point,
before the client received confirmation (or data) from the
server. This does not only affect
auto-commit statements though. If the
communication problem occurred during
Connection.commit(), the question arises
of whether the transaction was committed on the server
before the communication failed, or whether the server
received the commit request at all.
The second reason for the generation of exceptions is that transaction-scoped contextual data may be vulnerable, for example:
Temporary tables.
User-defined variables.
Server-side prepared statements.
These items are lost when a connection fails, and if the connection silently reconnects without generating an exception, this could be detrimental to the correct execution of your application.
In summary, communication errors generate conditions that may well be unsafe for Connector/J to simply ignore by silently reconnecting. It is necessary for the application to be notified. It is then for the application developer to decide how to proceed in the event of connection errors and failures.
15.14: How can I use 3-byte UTF8 with Connector/J?
To use 3-byte UTF8 with Connector/J set
characterEncoding=utf8 and set
useUnicode=true in the connection string.
15.15:
How can I use 4-byte UTF8, utf8mb4 with
Connector/J?
To use 4-byte UTF8 with Connector/J configure the MySQL
server with character_set_server=utf8mb4.
Connector/J will then use that setting as long as
characterEncoding has not been set in the
connection string. This is equivalent to autodetection of
the character set.
15.16:
Using useServerPrepStmts=false and
certain character encodings can lead to corruption when
inserting BLOBs. How can this be avoided?
When using certain character encodings, such as SJIS, CP932, and BIG5, it is possible that BLOB data contains characters that can be interpreted as control characters, for example, backslash, '\'. This can lead to corrupted data when inserting BLOBs into the database. There are two things that need to be done to avoid this:
Set the connection string option
useServerPrepStmts to
true.
Set SQL_MODE to
NO_BACKSLASH_ESCAPES.
Table of Contents
Oracle provides assistance to the user community by means of its mailing lists. For Connector/J related issues, you can get help from experienced users by using the MySQL and Java mailing list. Archives and subscription information is available online at http://lists.mysql.com/java.
For information about subscribing to MySQL mailing lists or to browse list archives, visit http://lists.mysql.com/. See MySQL Mailing Lists.
Community support from experienced users is also available through the JDBC Forum. You may also find help from other users in the other MySQL Forums, located at http://forums.mysql.com. See MySQL Community Support at the MySQL Forums.
The normal place to report bugs is http://bugs.mysql.com/, which is the address for our bugs database. This database is public, and can be browsed and searched by anyone. If you log in to the system, you will also be able to enter new reports.
If you have found a sensitive security bug in MySQL, you can
send email to <security@mysql.com>.
Writing a good bug report takes patience, but doing it right the first time saves time both for us and for yourself. A good bug report, containing a full test case for the bug, makes it very likely that we will fix the bug in the next release.
This section will help you write your report correctly so that you do not waste your time doing things that may not help us much or at all.
If you have a repeatable bug report, please report it to the bugs database at http://bugs.mysql.com/. Any bug that we are able to repeat has a high chance of being fixed in the next MySQL release.
To report other problems, you can use one of the MySQL mailing lists.
Remember that it is possible for us to respond to a message containing too much information, but not to one containing too little. People often omit facts because they think they know the cause of a problem and assume that some details do not matter.
A good principle is this: If you are in doubt about stating something, state it. It is faster and less troublesome to write a couple more lines in your report than to wait longer for the answer if we must ask you to provide information that was missing from the initial report.
The most common errors made in bug reports are (a) not including the version number of Connector/J or MySQL used, and (b) not fully describing the platform on which Connector/J is installed (including the JVM version, and the platform type and version number that MySQL itself is installed on).
This is highly relevant information, and in 99 cases out of 100, the bug report is useless without it. Very often we get questions like, “Why doesn't this work for me?” Then we find that the feature requested wasn't implemented in that MySQL version, or that a bug described in a report has already been fixed in newer MySQL versions.
Sometimes the error is platform-dependent; in such cases, it is next to impossible for us to fix anything without knowing the operating system and the version number of the platform.
If at all possible, create a repeatable, standalone testcase that doesn't involve any third-party classes.
To streamline this process, we ship a base class for testcases
with Connector/J, named
'com.mysql.jdbc.util.BaseBugReport'. To
create a testcase for Connector/J using this class, create your
own class that inherits from
com.mysql.jdbc.util.BaseBugReport and
override the methods setUp(),
tearDown() and
runTest().
In the setUp() method, create code that
creates your tables, and populates them with any data needed to
demonstrate the bug.
In the runTest() method, create code that
demonstrates the bug using the tables and data you created in
the setUp method.
In the tearDown() method, drop any tables
you created in the setUp() method.
In any of the above three methods, use one of the variants of
the getConnection() method to create a JDBC
connection to MySQL:
getConnection() - Provides a connection
to the JDBC URL specified in getUrl().
If a connection already exists, that connection is returned,
otherwise a new connection is created.
getNewConnection() - Use this if you
need to get a new connection for your bug report (that is,
there is more than one connection involved).
getConnection(String url) - Returns a
connection using the given URL.
getConnection(String url, Properties
props) - Returns a connection using the given URL
and properties.
If you need to use a JDBC URL that is different from
'jdbc:mysql:///test', override the method
getUrl() as well.
Use the assertTrue(boolean expression) and
assertTrue(String failureMessage, boolean
expression) methods to create conditions that must be
met in your testcase demonstrating the behavior you are
expecting (vs. the behavior you are observing, which is why you
are most likely filing a bug report).
Finally, create a main() method that
creates a new instance of your testcase, and calls the
run method:
public static void main(String[] args) throws Exception {
new MyBugReport().run();
}Once you have finished your testcase, and have verified that it demonstrates the bug you are reporting, upload it with your bug report to http://bugs.mysql.com/.
The Connector/J Change History (Changelog) is located with the main Changelog for MySQL. See Appendix A, MySQL Connector/J Change History.
Table of Contents
Fixes bugs found since release 5.1.20.
Bugs Fixed
With a connection encoding of gbk and a
server encoding of latin1, a call such as
PreparedStatement.setString(1, "0f0f0702")
could thrown an exception
java.lang.StringIndexOutOfBoundsException.
(Bug #13943893, Bug #64731)
When Connector/J was connected to a MySQL 5.5 server, the error message for an invalid query could be returned in the wrong character set and appear garbled. (Bug #13702427, Bug #64205)
The timezone entry was missing for “MEST - Middle European Summer Time”. (Bug #11748548, Bug #36662)
Specifying a non-existent character set in the
characterEncoding or
characterSetResults connection options could
produce a NullPointerException error. The
error could occur with a typographical mistake, such as using a
hyphen instead of an underscore in the name.
(Bug #11749010, Bug #37931)
Fixes bugs found since release 5.1.19.
Bugs Fixed
Important Change:
This fix corrects an issue introduced in Connector/J 5.1.19 that
caused connection errors with MySQL 4.1 and earlier servers. A
java.lang.ClassCastException exception
occurred during connection initialization when
com.mysql.jdbc.ConnectionImpl.buildCollationMapping()
interpreted the output of the SHOW COLLATION
statement.
(Bug #13958793)
Using Connector/J 5.1.19 in combination with JBoss could result
in an error while establishing a connection:
MySQLNonTransientConnectionException: Bad
handshake. This issue occurred when using the
old-style password hash, which requires the
mysql_old_password plugin during handshake. A
workaround was to replace the 16-byte hash with a 41-byte one,
as explained in Password Hashing in MySQL.
(Bug #13990612, Bug #64983)
A java.lang.StringIndexOutOfBoundsException
exception could occur when manipulating date/time values with
fractional seconds.
(Bug #13960556)
A MySQLSyntaxErrorException could occur when
calling certain methods while connected to a MySQL 5.6.5 or
higher server. Affected methods included
StatementImpl.execute() and
PreparedStatement.execute().
(Bug #13955027)
The savepoint identifier generated by the
java.sql.Connection#.setSavepoint() function
could be misinterpreted as a floating-point number, for example
values such as 123e10 or
123e10foo. Such values could cause
replication errors on slave servers because the values are not
quoted in the binary log. The fix ensures that the savepoint
identifiers do not begin with digits.
(Bug #11763271, Bug #55962)
If the string limit was used in a column
name, prepared statements incorrectly treated the statement as
if it used a LIMIT clause. For example, a
prepared statement with maxrows set to 0
could incorrectly reuse the value from a previous call to
setMaxRows(). This issue applied to both
quoted and unquoted column names, and server-side and
client-side prepared statements.
(Bug #11748492, Bug #36478)
Fixes bugs found since release 5.1.18.
Functionality Added or Changed
For a UTF-8 table using a collation other than the default
(utf8_general_ci), the precision of the
ResultSetMetaData could be different from the
precision specified in the CREATE
TABLE statement. The fix corrects the return value
from getMaxBytesPerChar().
This fix changes the behavior of some connection string
parameters. useDynamicCharsetInfo no longer
has any effect. With the setting
cacheServerConfiguration=true, the cached
settings also include the results of the SHOW CHARACTER
SET statement.
(Bug #13495590, Bug #63456)
Added support for pluggable authentication. via the
com.mysql.jdbc.AuthenticationPlugin interface
(which extends the standard “extension” interface).
Examples are in
com/mysql/jdbc/authentication and in
testsuite.regression.ConnectionRegressionTest.
This feature introduces three new connection properties:
authenticationPlugins defines a
comma-delimited list of classes that implement
com.mysql.jdbc.AuthenticationPlugin and
are used for authentication unless disabled by the
disabledAuthenticationPlugins property.
disabledAuthenticationPlugins defines a
comma-delimited list of classes implementing
com.mysql.jdbc.AuthenticationPlugin or
mechanisms, i.e. mysql_native_password.
The authentication plugins or mechanisms cannot be used for
authentication. Authentication will fail if it requires one
of these classes. It is an error to disable the default
authentication plugin, either the one named by
defaultAuthenticationPlugin property or
the hardcoded one if
defaultAuthenticationPlugin propery is
not set.
defaultAuthenticationPlugin defines the
name of a class implementing
com.mysql.jdbc.AuthenticationPlugin,
which is used as the default authentication plugin. It is an
error to use a class that is not listed in
authenticationPlugins and is not one of
the built-in plugins. It is an error to set as default a
plugin that is disabled by being listed in the
disabledAuthenticationPlugins property.
It is an error to set this value to null or the empty
string; there must be at least one valid default
authentication plugin specified for the connection, meeting
all the constraints listed above.
Bugs Fixed
Performance:
An unnecessary call to bind() during socket
operations could limit scalability on some platforms.
(Bug #13875070, Bug #63811)
setMaxRows was not correctly processed during
metadata collection for client-side prepared statements, causing
the entire result set to be fetched and possibly leading to an
out-of-memory error.
(Bug #13839395, Bug #64621)
A problem with processing escape sequences (in
com.mysql.jdbc.EscapeProcessor#escapeSQL)
could cause certain statements to fail. For example, a
CREATE TABLE statement with a clause such as
CONSTRAINT `fk_` was not parsed correctly.
(Bug #13612316, Bug #63526)
Underprivileged execution of stored procedures fixed. (Bug #13508993, Bug #61203)
A combination of failover connections, proxied or prepared
statements, and database connection pool could cause a memory
leak due to improper implementation of
equals().
(Bug #13441718, Bug #63284)
Reduced the memory overhead for server-side prepared statements.
Each prepared statement allocated a 4K buffer for converting
streams. Now this allocation is skipped when no
set*Stream() methods have been used.
The Connection.changeUser() method did not
check for closed connections, leading to
NullPointerException errors when this method
was called on a closed connection.
Fixes bugs found since release 5.1.17.
Functionality Added or Changed
Added the function
MYSQL_INDEX_TO_MYSQL_CHARSET to retrieve the
server charset name, using an index instead of parsing variables
to CharsetMapping.java
Bugs Fixed
The LRUCache implementation removed the
eldest entry, rather than the least-recently accessed.
(Bug #13036537)
Changed cacheCallableStatements to
cacheCallableStmts in
maxPerformance.properties, to allow proper
caching.
(Bug #13036309)
Added a new ant flag,
com.mysql.jdbc.junit.fork, which controls
whether JUnit will fork new processes.
The value on: The default, and legacy
behavior. Or off): Required for Windows, as
otherwise process fork failure errors will
result while running the test suite via ant
on Windows.
(Bug #12784170)
Not putting a space between
VALUES() and
ON
DUPLICATE KEY UPDATE causes connector/J to both (A)
Rewrite the query, although it includes an ON
UPDATE statement and (B) To generate the wrong query
with multiple
ON
DUPLICATE KEY statements.
(Bug #12565726)
The loadBalanceBlacklistTimeout option was
not functioning properly. Working connections were not being
removed from the blacklist.
(Bug #63135)
Connector/J now guards against the condition where a call to
KILL QUERY will
kill the next query issued by the server, if no query is in
process.
(Bug #61501)
The "old" warnings were returned when
Statement.getWarnings() was called after
Statement.clearWarnings().
(Bug #61866, Bug #12791594)
Calling Statement.cancel() on a statement
that isn't currently executing, will cause a later-executed
query on the same connection to be unexpectedly canceled. The
driver now guards against this condition, but it is an
underlying server issue. The MySQL statement
KILL QUERY
(which is what the driver uses to implement
Statement.cancel()) is rather
non-deterministic, and thus the use of
Statement.cancel() should be avoided if
possible.
(Bug #61501)
A connection could not be established when the
URL
contained both sessionVariables and
characterEncoding.
(Bug #61201, Bug #12649557)
Reverting changes made to
ConnectionImpl.java, the private
boolean characterSetNamesMatches function.
Fixes bugs found since release 5.1.16.
Bugs Fixed
LIKE was not optimized in then
server when run against INFORMATION_SCHEMA
tables and no wildcards were used. Databases/tables with
'_' or '%' in their names
(escaped or not) are handled by this code path, although slower,
since it is rare to find these characters in table names in SQL.
If there is a '_' or '%'
in the string, LIKE takes care of
that; otherwise, '=' is now used instead. The
only exception is the information_schema
database, which is handled separately. The patch covers both
getTables() and
getColumns().
(Bug #61332)
The first call to a stored procedure failed with “No
Database Selected”. The workaround introduced in
DatabaseMetaData.getCallStmtParameterTypes to
fix the server bug where SHOW CREATE
PROCEDURE was not respecting lowercase table names was
misbehaving when the connection was not attached to a database
and on case-insensitive operating systems.
(Bug #61150)
There was a concurrency bottleneck in Java's character set
encoding/decoding when converting bytes to/from
String values.
No longer use String.getBytes(...), or
new String(byte[]...). Use the
StringUtils method instead.
(Bug #61105)
Fixes bugs found since release 5.1.15.
Functionality Added or Changed
The Connection.isServerLocal() method can now
determine if a connection is against a server on the same host.
Bugs Fixed
When auto-reconnect was used with
cacheServerConfiguration, errors could occur
when the host changed (in an HA setup, for example).
(Bug #12325877)
DBMD.getTables and
getColumns fail with table names that contain
a dot (like "junk_[Sp:e,c/ C-h+a=.r]"). The
workaround is to use
useInformationSchema=True.
(Bug #11782297)
ResultSetRow.getTimestampFast and
getTime had invalid offsets.
(Bug #60313)
Fixed a bug where Connector/J would kill the matching
ConnectionID, but on the wrong server.
(Bug #54135)
wasNull was not set for a
DATE field with the value of
0000-00-00 in getDate(),
although zeroDateTimeBehavior is defined as
convertToNull.
(Bug #57808)
A bypassing of the server protocol bug, where the DB should be
null-terminated whether it exists or not. This affects
COM_CHANGE_USER.
(Bug #54425)
Fixed a timestamp offset bug in
com.mysql.jdbc.ResultSetRow.getTimestampFast().
(Bug #60313, Bug #11890729)
Fixes bugs found since release 5.1.14.
Bugs Fixed
Optional logging class
com.mysql.jdbc.log.Log4JLogger was not
included in the source/binary package for 5.1.14.
5.1.15 will ship with an SLF4J logger (which can then be plugged into Log4J). Unfortunately, it is not possible to ship a direct Log4J integration because the GPL is not compatible with Log4J's license. (Bug #59511, Bug #11766408)
The hard-coded list of reserved words in Connector/J was not updated to reflect the list of reserved words in MySQL Server 5.5. (Bug #59224)
MySqlProcedure accepted null arguments as parameters, however the JDBC meta data did not indicate that. (Bug #38367, Bug #11749186)
Using Connector/J to connect from a z/OS machine to a MySQL Server failed when the database name to connect to was included in the connection URL. This was because the name was sent in z/OS default platform encoding, but the MySQL Server expected Latin1.
It should be noted that when connecting from systems that do not
use Latin1 as the default platform encoding, the following
connection string options can be useful:
passwordCharacterEncoding=ASCII and
characterEncoding=ASCII.
(Bug #18086, Bug #11745647)
Fixes bugs found since release 5.1.13.
Functionality Added or Changed
Connector/J's load-balancing functionality only allowed the following events to trigger failover:
Transaction commit/rollback
CommunicationExceptions
Matches to user-defined Exceptions using the loadBalanceSQLStateFailover, loadBalanceSQLExceptionSubclassFailover or loadBalanceExceptionChecker property.
This meant that connections where auto-commit was enabled were not balanced, except for Exceptions, and this was problematic in the case of distribution of read-only work across slaves in a replication deployment.
The ability to load-balance while auto-commit is enabled has now been added to Connector/J. This introduces two new properties:
loadBalanceAutoCommitStatementThreshold - defines the number of matching statements which will trigger the driver to (potentially) swap physical server connections. The default value (0) retains the previously-established behavior that connections with auto-commit enabled are never balanced.
loadBalanceAutoCommitStatementRegex - the regular expression against which statements must match. The default value (blank) matches all statements.
Load-balancing will be done after the statement is executed, before control is returned to the application. If rebalancing fails, the driver will silently swallow the resulting Exception (as the statement itself completed successfully). (Bug #55723)
Bugs Fixed
Added diagnostic information to SQLException
messages that are caused by usage of a closed load-balanced
connection, to help clarify the root cause of a connection
closure.
(Bug #56200)
Connection failover left slave/secondary in read-only mode.
Failover attempts between two read-write masters did not
properly set
this.currentConn.setReadOnly(false).
(Bug #58706)
Connector/J mapped both 3-byte and 4-byte UTF8 encodings to the same Java UTF8 encoding.
To use 3-byte UTF8 with Connector/J set
characterEncoding=utf8 and set
useUnicode=true in the connection string.
To use 4-byte UTF8 with Connector/J configure the MySQL server
with character_set_server=utf8mb4.
Connector/J will then use that setting as long as
characterEncoding has not been set in the
connection string. This is equivalent to autodetection of the
character set.
(Bug #58232)
The CallableStatementRegression test suite
failed with a Null Pointer Exception because the
OUT parameter in the
I__S.PARAMETERS table had no name, that is
COLUMN_NAME had the value
NULL.
(Bug #58232)
Attempting to use JDBC4 functions on
Connection objects resulted in errors being
generated:
Exception in thread "main" java.lang.AbstractMethodError: com.mysql.jdbc.LoadBalancedMySQLConnection.createBlob()Ljava/sql/Blob; at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.mysql.jdbc.LoadBalancingConnectionProxy.invoke(LoadBalancingConnectionProxy.java:476) at $Proxy0.createBlob(Unknown Source)
(Bug #56099)
DatabaseMetaData.supportsMultipleResultSets()
was hard-coded to return false, even though
Connector/J supports multiple result sets.
(Bug #57380)
Invoking a stored procedure containing output parameters by its full name, where the procedure was located in another database, generated the following exception:
Parameter index of 1 is out of range (1, 0)
(Bug #57022)
Using the useOldUTF8Behavior parameter failed
to set the connection character set to latin1
as required.
In versions prior to 5.1.3, the handshake was done using
latin1, and while there was logic in place to
explicitly set the character set after the handshake was
complete, this was bypassed when
useOldUTF8Behavior was true. This was not a
problem until 5.1.3, when the handshake was modified to use
utf8, but the logic continued to allow the
character set configured during that handshake process to be
retained for later use. As a result,
useOldUTF8Behavior effectively failed.
(Bug #57262)
Leaving Trust/ClientCertStoreType properties unset caused an
exception to be thrown when connecting with
useSSL=true, as no default was used.
(Bug #56955)
When a JDBC client disconnected from a remote server using
Connection.close(), the TCP connection
remained in the TIME_WAIT state on the server
side, rather than on the client side.
(Bug #56979)
When load-balanced connections swap servers, certain session state was copied from the previously active connection to the newly-selected connection. State synchronized included:
Auto-commit state
Transaction isolation state
Current schema/catalog
However, the read-only state was not synchronized, which caused problems if a write was attempted on a read-only connection. (Bug #56706)
When using Connector/J configured for failover (jdbc:mysql://host1,host2,... URLs), the non-primary servers re-balanced when the transactions on the master were committed or rolled-back. (Bug #56429)
An unhandled Null Pointer Exception (NPE) was generated in
DatabaseMetaData.java when calling an
incorrectly cased function name where no permission to access
mysql.proc was available.
In addition to catching potential NPEs, a guard against calling
JDBC functions with db_name.proc_name
notation was also added.
(Bug #56305)
Fixes bugs found since release 5.1.12.
Functionality Added or Changed
Connector/J did not support utf8mb4 for
servers 5.5.2 and newer.
Connector/J now auto-detects servers configured with
character_set_server=utf8mb4 or treats the
Java encoding utf-8 passed using
characterEncoding=... as
utf8mb4 in the SET NAMES=
calls it makes when establishing the connection.
(Bug #54175)
Bugs Fixed
When the allowMultiQueries connection string
option was set to true, a call to
Statement.executeBatch() scanned the query
for escape codes, even though
setEscapeProcessing(false) had been called
previously.
(Bug #51704)
The method unSafeStatementInterceptors()
contained an erroneous line of code, which resulted in the
interceptor being called, but the result being thrown away.
(Bug #53041)
There was a performance regression of roughly 25% between r906 and r907, which appeared to be caused by pushing the Proxy down to the I/O layer. (Bug #52534)
In the file DatabaseMetadata.java, the
function private void
getCallStmtParameterTypes failed if the parameter was
defined over more than one line by using the '\n' character.
(Bug #52167)
The catalog parameter, PARAM_CAT, was not
correctly processed when calling for metadata with
getMetaData() on stored procedures. This was
because PARAM_CAT was hardcoded in the code
to NULL. In the case where
nullcatalogmeanscurrent was
true, which is its default value, a crash did
not occur, but the metadata returned was for the stored
procedures from the catalog currently attached to. If, however,
nullcatalogmeanscurrent was set to
false then a crash resulted.
Connector/J has been changed so that when
NULL is passed as
PARAM_CAT it will not crash when
nullcatalogmeanscurrent is
false, but rather iterate all catalogs in
search of stored procedures. This means that
PARAM_CAT is no longer hardcoded to
NULL (see Bug #51904).
(Bug #51912)
Logic in implementations of
LoadBalancingConnectionProxy and
LoadBalanceStrategy behaved differently as to
which SQLExceptions trigger failover to a new
host. The former looked at the first two characters of the
SQLState:
if (sqlState.startsWith("08"))
...The latter used a different test:
if (sqlEx instanceof CommunicationsException
|| "08S01".equals(sqlEx.getSQLState())) {
...
This meant it was possible for a new
Connection object to throw an
Exception when the first selected host was
unavailable. This happened because
MySqlIO.createNewIO() could throw an
SQLException with a
SQLState of “08001”, which did
not trigger the “try another host” logic in the
LoadBalanceStrategy implementations, so an
Exception was thrown after having only
attempted connecting to a single host.
(Bug #52231)
A load balanced Connection object with
multiple open underlying physical connections rebalanced on
commit(), rollback(), or
on a communication exception, without validating the existing
connection. This caused a problem when there was no pinging of
the physical connections, using queries starting with “/*
ping */”, to ensure they remained active. This meant that
calls to Connection.commit() could throw a
SQLException. This did not occur when the
transaction was actually committed; it occurred when the new
connection was chosen and the driver attempted to set the
auto-commit or transaction isolation state on the newly chosen
physical connection.
(Bug #51783)
The rollback() method could fail to rethrow a
SQLException if the server became unavailable
during a rollback. The errant code only rethrew when
ignoreNonTxTables was true and the exception
did not have the error code 1196,
SQLError.ER_WARNING_NOT_COMPLETE_ROLLBACK.
(Bug #51776)
Objects created by ConnectionImpl, such as
prepared statements, hold a reference to the
ConnectionImpl that created them. However,
when the load balancer picked a new connection, it did not
update the reference contained in, for example, the
PreparedStatement. This resulted in inserts
and updates being directed to invalid connections, while commits
were directed to the new connection. This resulted in silent
data loss.
(Bug #51643)
When a StatementInterceptor was used and an
alternate ResultSet was returned from
preProcess(), the original statement was
still executed.
(Bug #51666)
jdbc:mysql:loadbalance:// would connect to
the same host, even though
loadBalanceStrategy was set to a value of
random, and multiple hosts were specified.
(Bug #51266)
An unexpected exception when trying to register
OUT parameters in
CallableStatement.
Sometimes Connector/J was not able to register
OUT parameters for
CallableStatements.
(Bug #43576)
Fixes bugs found since release 5.1.11.
Bugs Fixed
The catalog parameter was ignored in the
DatabaseMetaData.getProcedure() method. It
returned all procedures in all databases.
(Bug #51022)
A call to DatabaseMetaData.getDriverVersion()
returned the revision as mysql-connector-java-5.1.11 (
Revision: ${svn.Revision} ). The variable
${svn.Revision} was not replaced by the SVN
revision number.
(Bug #50288)
Fixes bugs found since release 5.1.10.
Functionality Added or Changed
Replication connections, those with URLs that start with
jdbc:mysql:replication, now use a jdbc:mysql:loadbalance
connection for the slave pool. This means that it is possible to
set load balancing properties such as
loadBalanceBlacklistTimeout and
loadBalanceStrategy to choose a mechanism for
balancing the load, and failover or fault tolerance strategy for
the slave pool.
(Bug #49537)
Bugs Fixed
NullPointerException sometimes occurred in
invalidateCurrentConnection() for
load-balanced connections.
(Bug #50288)
For pooled connections, Connector/J did not process the session
variable time_zone when set using the URL,
resulting in incorrect timestamp values being stored.
(Bug #49700)
The deleteRow method caused a full table
scan, when using an updatable cursor and a multibyte character
set.
(Bug #49745)
The ExceptionInterceptor class did not
provide a Connection context.
(Bug #49607)
Ping left closed connections in the liveConnections map, causing subsequent Exceptions when that connection was used. (Bug #48605)
Using MysqlConnectionPoolDataSource with a
load-balanced URL generated exceptions of type
ClassCastException:
ClassCastException in MysqlConnectionPoolDataSource Caused by: java.lang.ClassCastException: $Proxy0 at com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource.getPooledConnection(MysqlConne ctionPoolDataSource.java:80)
java.lang.ClassCastException: $Proxy2 at com.mysql.jdbc.jdbc2.optional.StatementWrapper.executeQuery(StatementWrapper.java:744)
(Bug #48486)
The implementation for load-balanced
Connection used a proxy, which delegated
method calls, including equals() and
hashCode(), to underlying
Connection objects. This meant that
successive calls to hashCode() on the same
object potentially returned different values, if the proxy state
had changed such that it was utilizing a different underlying
connection.
(Bug #48442)
The batch rewrite functionality attempted to identify the start
of the VALUES list by looking for
“VALUES ” (with trailing space). However, valid
MySQL syntax permits VALUES to be followed by
whitespace or an opening parenthesis:
INSERT INTO tbl VALUES (1); INSERT INTO tbl VALUES(1);
Queries written with the above formats did not therefore gain the performance benefits of the batch rewrite. (Bug #48172)
A PermGen memory leaked was caused by the Connector/J statement
cancellation timer (java.util.Timer). When
the application was unloaded the cancellation timer did not
terminate, preventing the ClassLoader from being garbage
collected.
(Bug #36565)
With the connection string option
noDatetimeStringSync set to
true, and server-side prepared statements
enabled, the following exception was generated if an attempt was
made to obtain, using ResultSet.getString(),
a datetime value containing all zero components:
java.sql.SQLException: Value '0000-00-00' can not be represented as java.sql.Date
(Bug #32525)
Fixes bugs found since release 5.1.9.
Bugs Fixed
The DriverManager.getConnection() method
ignored a non-standard port if it was specified in the JDBC
connection string. Connector/J always used the standard port
3306 for connection creation. For example, if the string was
jdbc:mysql://localhost:6777, Connector/J
would attempt to connect to port 3306, rather than 6777.
(Bug #47494)
Bugs Fixed
When Connector/J encountered an error condition that caused it
to create a CommunicationsException, it tried
to build a friendly error message that helped diagnose what was
wrong. However, if there had been no network packets received
from the server, the error message contained the following
incorrect text:
The last packet successfully received from the server was 1,249,932,468,916 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago.
(Bug #46637)
In the class
com.mysql.jdbc.jdbc2.optional.SuspendableXAConnection,
which is used when
pinGlobalTxToPhysicalConnection=true, there
is a static map (XIDS_TO_PHYSICAL_CONNECTIONS) that tracks the
Xid with the XAConnection, however this map was not populated.
The effect was that the
SuspendableXAConnection was never pinned to
the real XA connection. Instead it created new connections on
calls to start, end,
resume, and prepare.
(Bug #46925)
When using the ON DUPLICATE KEY UPDATE functionality together with the rewriteBatchedStatements option set to true, an exception was generated when trying to execute the prepared statement:
INSERT INTO config_table (modified,id_) VALUES (?,?) ON DUPLICATE KEY UPDATE modified=?
The exception generated was:
java.sql.SQLException: Parameter index out of range (3 > number of parameters, which is 2). at com.sag.etl.job.processors.JdbcInsertProcessor.flush(JdbcInsertProcessor.java:135) ...... Caused by: java.sql.SQLException: Parameter index out of range (3 > number of parameters, which is 2). at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926) at com.mysql.jdbc.PreparedStatement.checkBounds(PreparedStatement.java:3657) at com.mysql.jdbc.PreparedStatement.setInternal(PreparedStatement.java:3641) at com.mysql.jdbc.PreparedStatement.setBytesNoEscapeNoQuotes(PreparedStatement.java:3391) at com.mysql.jdbc.PreparedStatement.setOneBatchedParameterSet(PreparedStatement.java:4203) at com.mysql.jdbc.PreparedStatement.executeBatchedInserts(PreparedStatement.java:1759) at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1441) at com.sag.etl.job.processors.JdbcInsertProcessor.flush(JdbcInsertProcessor.java:131) ... 16 more
(Bug #46788)
Accessing result set columns by name after the result set had been closed resulted in a NullPointerException instead of a SQLException. (Bug #41484)
The getSuperTypes method returned a result
set with incorrect names for the first two columns. The name of
the first column in the result set was expected to be
TYPE_CAT and that of the second column
TYPE_SCHEM. The method however returned the
names as TABLE_CAT and
TABLE_SCHEM for first and second column
respectively.
(Bug #44508)
Calling ResultSet.deleteRow() on a table with
a primary key of type BINARY(8) silently
failed to delete the row, but only in some repeatable cases. The
generated DELETE statement generated
corrupted part of the primary key data. Specifically, one of the
bytes was changed from 0x90 to 0x9D, although the corruption
appeared to be different depending on whether the application
was run on Windows or Linux.
(Bug #43759)
SQLException for data truncation error gave the error code as 0 instead of 1265. (Bug #44324)
QueryTimeout did not work for batch
statements waiting on a locked table.
When a batch statement was issued to the server and was forced to wait because of a locked table, Connector/J only terminated the first statement in the batch when the timeout was exceeded, leaving the rest hanging. (Bug #34555)
The parseURL method in class
com.mysql.jdbc.Driver did not work as
expected. When given a URL such as
“jdbc:mysql://www.mysql.com:12345/my_database” to
parse, the property PORT_PROPERTY_KEY was
found to be null and the
HOST_PROPERTY_KEY property was found to be
“www.mysql.com:12345”.
Connector/J has been fixed so that it will now always fill in
the PORT property (using 3306 if not
specified), and the HOST property (using
localhost if not specified) when
parseURL() is called. The driver also
parses a list of hosts into HOST.n and
PORT.n properties as well as adding a
property NUM_HOSTS for the number of hosts
it has found. If a list of hosts is passed to the driver,
HOST and PORT will be
set to the values given by HOST.1 and
PORT.1 respectively. This change has
centralized and cleaned up a large section of code used to
generate lists of hosts, both for load-balanced and fault
tolerant connections and their tests.
(Bug #32216)
Attempting to delete rows using
ResultSet.deleteRow() did not delete rows
correctly.
(Bug #27431)
The setDate method silently ignored the
Calendar parameter. The code was implemented as follows:
public void setDate(int parameterIndex, java.sql.Date x, Calendar cal) throws SQLException {
setDate(parameterIndex, x);
}
From reviewing the code it was apparent that the Calendar
parameter cal was ignored.
(Bug #23584)
Bugs Fixed
Calling Connection.serverPreparedStatement()
variants that do not take result set type or concurrency
arguments returned statements that produced result sets with
incorrect defaults, namely
TYPE_SCROLL_SENSITIVE.
(Bug #45171)
The reported milliseconds since the last server packets were received/sent was incorrect by a factor of 1000. For example, the following method call:
SQLError.createLinkFailureMessageBasedOnHeuristics( (ConnectionImpl) this.conn, System.currentTimeMillis() - 1000, System.currentTimeMillis() - 2000, e, false);
returned the following string:
The last packet successfully received from the server was 2 milliseconds ago. The last packet sent successfully to the server was 1 milliseconds ago.
(Bug #45419)
The method Statement.getGeneratedKeys() did
not return values for UNSIGNED BIGINTS with
values greater than Long.MAX_VALUE.
Unfortunately, because the server does not tell clients what
TYPE the auto increment value is, the driver cannot consistently
return BigIntegers for the result set returned from
getGeneratedKeys(), it will only return them
if the value is greater than Long.MAX_VALUE.
If your application needs this consistency, it will need to
check the class of the return value from
.getObject() on the ResultSet returned by
Statement.getGeneratedKeys() and if it is not
a BigInteger, create one based on the
java.lang.Long that is returned.
(Bug #43196)
A statement interceptor received the incorrect parameters when used with a batched statement. (Bug #39426)
When using Connector/J 5.1.7 to connect to MySQL Server 4.1.18 the following error message was generated:
Thu Dec 11 17:38:21 PST 2008 WARN: Invalid value {1} for server variable named {0},
falling back to sane default of {2}
This occurred with MySQL Server version that did not support
auto_increment_increment. The error message
should not have been generated.
(Bug #41416)
The RETURN_GENERATED_KEYS flag was being
ignored. For example, in the following code the
RETURN_GENERATED_KEYS flag was ignored:
PreparedStatement ps = connection.prepareStatement("INSERT INTO table
values(?,?)",PreparedStatement.RETURN_GENERATED_KEYS);(Bug #41448)
Using Connector/J 5.1.6 the method
ResultSet.getObject returned a
BYTE[] for following:
SELECT TRIM(rowid) FROM tbl
Where rowid had a type of INT(11)
PRIMARY KEY AUTO_INCREMENT.
The expected return type was one of CHAR,
VARCHAR, CLOB, however, a
BYTE[] was returned.
Further, adding
functionsNeverReturnBlobs=true to the
connection string did not have any effect on the return type.
(Bug #38387)
Connector/J generated an unhandled
StringIndexOutOfBoundsException:
java.lang.StringIndexOutOfBoundsException: String index out of range: -1 at java.lang.String.substring(String.java:1938) at com.mysql.jdbc.EscapeProcessor.processTimeToken(EscapeProcessor.java:353) at com.mysql.jdbc.EscapeProcessor.escapeSQL(EscapeProcessor.java:257) at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1546) at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1524)
(Bug #42253)
When using rewriteBatchedStatements=true
with:
INSERT INTO table_name_values (...) VALUES (...)
Query rewriting failed because “values” at the end of the table name was mistaken for the reserved keyword. The error generated was as follows:
testBug40439(testsuite.simple.TestBug40439)java.sql.BatchUpdateException: You have an
error in your SQL syntax; check the manual that corresponds to your MySQL server version
for the right syntax to use near 'values (2,'toto',2),(id,data, ordr) values
(3,'toto',3),(id,data, ordr) values (' at line 1
at com.mysql.jdbc.PreparedStatement.executeBatchedInserts(PreparedStatement.java:1495)
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1097)
at testsuite.simple.TestBug40439.testBug40439(TestBug40439.java:42)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at testsuite.simple.TestBug40439.main(TestBug40439.java:57)(Bug #40439)
Error message strings contained variable values that were not expanded. For example:
Mon Nov 17 11:43:18 JST 2008 WARN: Invalid value {1} for server variable named {0},
falling back to sane default of {2}(Bug #40772)
When accessing a result set column by name using
ResultSetImpl.findColumn() an exception was
generated:
java.lang.NullPointerException at com.mysql.jdbc.ResultSetImpl.findColumn(ResultSetImpl.java:1103) at com.mysql.jdbc.ResultSetImpl.getShort(ResultSetImpl.java:5415) at org.apache.commons.dbcp.DelegatingResultSet.getShort(DelegatingResultSet.java:219) at com.zimbra.cs.db.DbVolume.constructVolume(DbVolume.java:297) at com.zimbra.cs.db.DbVolume.get(DbVolume.java:197) at com.zimbra.cs.db.DbVolume.create(DbVolume.java:95) at com.zimbra.cs.store.Volume.create(Volume.java:227) at com.zimbra.cs.store.Volume.create(Volume.java:189) at com.zimbra.cs.service.admin.CreateVolume.handle(CreateVolume.java:48) at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEngine.java:428) at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:285)
(Bug #41484)
If there was an apostrophe in a comment in a statement that was
being sent through Connector/J, the apostrophe was still
recognized as a quote and put the state machine in
EscapeTokenizer into the
inQuotes state. This led to further parse
errors.
For example, consider the following statement:
String sql = "-- Customer's zip code will be fixed\n" +
"update address set zip_code = 99999\n" +
"where not regexp '^[0-9]{5}([[.-.]])?([0-9]{4})?$'";
When passed through Connector/J, the
EscapeTokenizer did not recognize that the
first apostrophe was in a comment and thus set
inQuotes to true. When that happened, the
quote count was incorrect and thus the regular expression did
not appear to be in quotation marks. With the parser not
detecting that the regular expression was in quotation marks,
the curly braces were recognized as escape sequences and were
removed from the regular expression, breaking it. The server
thus received SQL such as:
-- Customer's zip code will be fixed update address set zip_code = '99999' where not regexp '^[0-9]([[.-.]])?([0-9])?$'
(Bug #41566)
Using useInformationSchema with
DatabaseMetaData.getExportedKeys() generated
the following exception:
com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Column 'REFERENCED_TABLE_NAME' in where clause is ambiguous ... at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1772) at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1923) at com.mysql.jdbc.DatabaseMetaDataUsingInfoSchema.executeMetadataQuery( DatabaseMetaDataUsingInfoSchema.java:50) at com.mysql.jdbc.DatabaseMetaDataUsingInfoSchema.getExportedKeys( DatabaseMetaDataUsingInfoSchema.java:603)
(Bug #43714)
The
SQLError.createLinkFailureMessageBasedOnHeuristics()
method created a message text for communication link failures.
When certain conditions were met, this message included both
“last packet sent” and “last packet
received” information, but when those conditions were not
met, only “last packet sent” information was
provided.
Information about when the last packet was successfully received should be provided in all cases. (Bug #44587)
When DatabaseMetaData.getProcedureColumns()
was called, the value for LENGTH was always
returned as 65535, regardless of the column type (fixed or
variable) or the actual length of the column.
However, if you obtained the PRECISION value,
this was correct for both fixed and variable length columns.
(Bug #41269)
The DEFERRABILITY column in database metadata
result sets was expected to be of type SHORT.
However, Connector/J returned it as INTEGER.
This affected the following methods:
getImportedKeys(),
getExportedKeys(),
getCrossReference().
(Bug #44867)
The result set returned by getIndexInfo() did
not have the format defined in the JDBC API specifications. The
fourth column, DATA_TYPE, of the result set
should be of type BOOLEAN. Connector/J
however returns CHAR.
(Bug #44869)
The result set returned by getTypeInfo() did
not have the format defined in the JDBC API specifications. The
second column, DATA_TYPE, of the result set
should be of type INTEGER. Connector/J
however returns SMALLINT.
(Bug #44868)
The result set returned by getColumns() did
not have the format defined in the JDBC API specifications. The
fifth column, DATA_TYPE, of the result set
should be of type INTEGER. Connector/J
however returns SMALLINT.
(Bug #44865)
The result set returned by
getVersionColumns() did not have the format
defined in the JDBC API specifications. The third column,
DATA_TYPE, of the result set should be of
type INTEGER. Connector/J however returns
SMALLINT.
(Bug #44863)
The result set returned by
getBestRowIdentifier() did not have the
format defined in the JDBC API specifications. The third column,
DATA_TYPE, of the result set should be of
type INTEGER. Connector/J however returns
SMALLINT.
(Bug #44862)
Connector/J contains logic to generate a message text
specifically for streaming result sets when there are
CommunicationsException exceptions generated.
However, this code was never reached.
In the CommunicationsException code:
private boolean streamingResultSetInPlay = false;
public CommunicationsException(ConnectionImpl conn, long lastPacketSentTimeMs,
long lastPacketReceivedTimeMs, Exception underlyingException) {
this.exceptionMessage = SQLError.createLinkFailureMessageBasedOnHeuristics(conn,
lastPacketSentTimeMs, lastPacketReceivedTimeMs, underlyingException,
this.streamingResultSetInPlay);
streamingResultSetInPlay was always false,
which in the following code in
SQLError.createLinkFailureMessageBasedOnHeuristics()
never being executed:
if (streamingResultSetInPlay) {
exceptionMessageBuf.append(
Messages.getString("CommunicationsException.ClientWasStreaming")); //$NON-NLS-1$
} else {
...(Bug #44588)
SQL injection was possible when using a string containing U+00A5 in a client-side prepared statement, and the character set being used was SJIS/Windows-31J. (Bug #41730)
Statement.getGeneratedKeys() retained result
set instances until the statement was closed. This caused memory
leaks for long-lived statements, or statements used in tight
loops.
(Bug #44056)
MySQL Connector/J 5.1.7 was slower than previous versions when
the rewriteBatchedStatements option was set
to true.
The performance regression in
indexOfIgnoreCaseRespectMarker()has been
fixed. It has also been made possible for the driver to
rewrite INSERT statements with ON
DUPLICATE KEY UPDATE clauses in them, as long as the
UPDATE clause contains no reference to
LAST_INSERT_ID(), as that would cause the
driver to return bogus values for
getGeneratedKeys() invocations. This has
resulted in improved performance over version 5.1.7.
(Bug #41532)
LoadBalancingConnectionProxy.doPing() did not
have blacklist awareness.
LoadBalancingConnectionProxy implemented
doPing() to ping all underlying connections,
but it threw any exceptions it encountered during this process.
With the global blacklist enabled, it catches these exceptions, adds the host to the global blacklist, and only throws an exception if all hosts are down. (Bug #43421)
When connecting with traceProtocol=true, no
trace data was generated for the server greeting or login
request.
(Bug #43070)
When the MySQL Server was upgraded from 4.0 to 5.0, the Connector/J application then failed to connect to the server. This was because authentication failed when the application ran from EBCDIC platforms such as z/OS. (Bug #43071)
A ConcurrentModificationException was
generated in LoadBalancingConnectionProxy:
java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(Unknown Source) at java.util.HashMap$KeyIterator.next(Unknown Source) at com.mysql.jdbc.LoadBalancingConnectionProxy.getGlobalBlacklist(LoadBalancingConnectionProxy.java:520) at com.mysql.jdbc.RandomBalanceStrategy.pickConnection(RandomBalanceStrategy.java:55) at com.mysql.jdbc.LoadBalancingConnectionProxy.pickNewConnection(LoadBalancingConnectionProxy.java:414) at com.mysql.jdbc.LoadBalancingConnectionProxy.invoke(LoadBalancingConnectionProxy.java:390)
(Bug #42055)
PreparedStatement.addBatch() did not check
for all parameters being set, which led to inconsistent behavior
in executeBatch(), especially when rewriting
batched statements into multi-value INSERTs.
(Bug #41161)
Functionality Added or Changed
When statements include ON DUPLICATE UPDATE,
and rewriteBatchedStatements is set to true,
batched statements are not rewritten into the form
INSERT INTO table VALUES (), (), (), instead
the statements are executed sequentially.
Bugs Fixed
When using trustCertificateKeyStoreUrl or
clientCertificateKeyStoreUrl, an
IllegalStateException was caused by an
uninitialized TrustManagerFactoryImpl object.
(Bug #11748637, Bug #36948, Bug #38192)
Statement.getGeneratedKeys() returned two
keys when using ON DUPLICATE KEY UPDATE and
the row was updated, not inserted.
(Bug #42309)
When configuring the Java Replication Driver the last slave specified was never used. (Bug #39611)
When using the replication driver with
autoReconnect=true, Connector/J checks in
PreparedStatement.execute (also called by
CallableStatement.execute) to determine if
the first character of the statement is an “S”, in
an attempt to block all statements that are not read-only-safe,
for example non-SELECT
statements. However, this also blocked
CALLs to stored procedures, even
if the stored procedures were defined as SQL READ
DATA or NO SQL.
(Bug #40031)
When the LoadBalancingConnectionProxy handles
a SQLException with SQL state starting with
“08”, it calls
invalidateCurrentConnection, which in turn
removes that Connection from
liveConnections and the
connectionsToHostsMap, but it did not add the
host to the new global blacklist, if the global blacklist was
enabled.
There was also the possibility of a
NullPointerException when trying to update
stats, where
connectionsToHostsMap.get(this.currentConn)
was called:
int hostIndex = ((Integer) this.hostsToListIndexMap.get(this.connectionsToHostsMap.get(this.currentConn))).intValue();
This could happen if a client tried to issue a rollback after
catching a SQLException caused by a
connection failure.
(Bug #39784)
When using the random load balancing strategy and starting with
two servers that were both unavailable, an
IndexOutOfBoundsException was generated when
removing a server from the whiteList.
(Bug #38782)
With large result sets ResultSet.findColumn
became a performance bottleneck.
(Bug #39962)
Connector/J ignored the value of the MySQL Server variable
auto_increment_increment.
(Bug #39956)
When an INSERT ON DUPLICATE KEY UPDATE was
performed, and the key already existed, the
affected-rows value was returned as 1 instead
of 0.
(Bug #39352)
Connector/J failed to parse
TIMESTAMP strings for nanos
correctly.
(Bug #39911)
Connector/J threw the following exception when using a read-only connection:
java.sql.SQLException: Connection is read-only. Queries leading to data modification are not allowed.
(Bug #38747)
Connector/J was unable to connect when using a
non-latin1 password.
(Bug #37570)
The useOldAliasMetadataBehavior connection
property was ignored.
(Bug #35753)
When getGeneratedKeys() was called on a
statement that had not been created with
RETURN_GENERATED_KEYS, no exception was
thrown, and batched executions then returned erroneous values.
(Bug #34185)
The loadBalance
bestResponseTime blacklists did not have a
global state.
(Bug #33861)
Incorrect result is returned from
isAfterLast() in streaming
ResultSet when using
setFetchSize(Integer.MIN_VALUE).
(Bug #35170)
Functionality Added or Changed
Multiple result sets were not supported when using streaming
mode to return data. Both normal statements and the result sets
from stored procedures now return multiple results sets, with
the exception of result sets using registered
OUTPUT parameters.
(Bug #33678)
Add the verifyServerCertificate property. If
set to "false" the driver will not verify the server's
certificate when useSSL is set to "true"
When using this feature, the keystore parameters should be
specified by the clientCertificateKeyStore*
properties, rather than system properties, as the JSSE doesn't
it straightforward to have a nonverifying trust store and the
"default" key store.
The profiler event handling has been made extensible using the
profilerEventHandler connection property.
XAConnections and datasources have been updated to the JDBC-4.0 standard.
Bugs Fixed
Prepared statements from pooled connections caused a
NullPointerException when
closed() under JDBC-4.0.
(Bug #35489)
When useServerPrepStmts=true and slow query
logging is enabled, the connector throws a
NullPointerException when it encounters a
slow query.
(Bug #35666)
The JDBC driver uses a different method for evaluating column
names in
resultsetmetadata.getColumnName() and
when looking for a column in
resultset.getObject(columnName). This
causes Hibernate to fail in queries where the two methods yield
different results, for example in queries that use alias names:
SELECT column AS aliasName from table
(Bug #35150)
DatabaseMetaData.getColumns() returns
incorrect COLUMN_SIZE value for
SET column.
(Bug #36830)
When trying to read Time values like
“00:00:00” with
ResultSet.getTime(int) an exception is
thrown.
(Bug #36051)
When using the keyword “loadbalance” in the connection string and trying to perform load balancing between two databases, the driver appears to hang. (Bug #35660)
JDBC data type getter method was changed to accept only column name, whereas previously it accepted column label. (Bug #35610)
In calling a stored function returning a
bigint, an exception is encountered
beginning:
java.sql.SQLException: java.lang.NumberFormatException: For input string:
followed by the text of the stored function starting after the argument list. (Bug #35199)
JDBC connection URL parameters is ignored when using
MysqlConnectionPoolDataSource.
(Bug #35810)
Retrieving the server version information for an active connection could return invalid information if the default character encoding on the host was not ASCII compatible. (Bug #31192)
MysqlConnectionPoolDataSource does not
support ReplicationConnection. Notice that we
implemented com.mysql.jdbc.Connection for
ReplicationConnection, however, only
accessors from ConnectionProperties are implemented (not the
mutators), and they return values from the currently active
connection. All other methods from
com.mysql.jdbc.Connection are implemented,
and operate on the currently active connection, with the
exception of resetServerState() and
changeUser().
(Bug #34937)
When calling isValid() on an active
connection, if the timeout is nonzero then the
Connection is invalidated even if the
Connection is valid.
(Bug #34703)
When retrieving the column type name of a geometry field, the
driver would return UNKNOWN instead of
GEOMETRY.
(Bug #34194)
The internal class
ResultSetInternalMethods referenced the
nonpublic class
com.mysql.jdbc.CachedResultSetMetaData.
(Bug #33823)
ResultSet.getTimestamp() would throw a
NullPointerException instead of a
SQLException when called on an empty
ResultSet.
(Bug #33162)
ResultSet.getTimestamp() returns incorrect
values for month/day of
TIMESTAMPs when using server-side
prepared statements (not enabled by default).
(Bug #34913)
RowDataStatic doesn't always set the
metadata in ResultSetRow, which can lead
to failures when unpacking DATE,
TIME,
DATETIME and
TIMESTAMP types when using
absolute, relative, and previous result set navigation methods.
(Bug #34762)
It was not possible to truncate a
BLOB using
Blog.truncate() when using 0 as an argument.
(Bug #34677)
Statements with batched values do not return correct values for
getGeneratedKeys() when
rewriteBatchedStatements is set to
true, and the statement has an ON
DUPLICATE KEY UPDATE clause.
(Bug #34093)
A NullPointerException could be raised when
using client-side prepared statements and enabled the prepared
statement cache using the cachePrepStmts.
(Bug #33734)
When using a cursor fetch for a statement, the internal prepared statement could cause a memory leak until the connection was closed. The internal prepared statement is now deleted when the corresponding result set is closed. (Bug #34518)
Using server side cursors and cursor fetch, the table metadata information would return the data type name instead of the column name. (Bug #33594)
ResultSet returned by
Statement.getGeneratedKeys() is not closed
automatically when statement that created it is closed.
(Bug #30508)
Load balancing connection using best response time would incorrectly "stick" to hosts that were down when the connection was first created.
We solve this problem with a black list that is used during the
picking of new hosts. If the black list ends up including all
configured hosts, the driver will retry for a configurable
number of times (the retriesAllDown
configuration property, with a default of 120 times), sleeping
250ms between attempts to pick a new connection.
We've also went ahead and made the balancing strategy
extensible. To create a new strategy, implement the interface
com.mysql.jdbc.BalanceStrategy (which
also includes our standard "extension" interface), and tell the
driver to use it by passing in the class name using the
loadBalanceStrategy configuration property.
(Bug #32877)
Using CallableStatement.setNull() on a
stored function would throw an
ArrayIndexOutOfBounds exception when setting
the last parameter to null.
(Bug #31823)
When using a connection from
ConnectionPoolDataSource, some
Connection.prepareStatement() methods would
return null instead of the prepared statement.
(Bug #32101)
MysqlValidConnectionChecker doesn't
properly handle connections created using
ReplicationConnection.
(Bug #31790)
During a Daylight Savings Time (DST) switchover, there was no way to store two timestamp/datetime values , as the hours end up being the same when sent as the literal that MySQL requires.
Note that to get this scenario to work with MySQL (since it
doesn't support per-value timezones), you need to configure your
server (or session) to be in UTC, and tell the driver not to use
the legacy date/time code by setting
useLegacyDatetimeCode to "false". This will
cause the driver to always convert to/from the server and client
timezone consistently.
This bug fix also fixes Bug #15604, by adding entirely new
date/time handling code that can be switched on by
useLegacyDatetimeCode being set to "false" as a
JDBC configuration property. For Connector/J 5.1.x, the default
is "true", in trunk and beyond it will be "false" (that is, the
old date/time handling code will be deprecated)
(Bug #32577, Bug #15604)
When unpacking rows directly, we don't hand off error message packets to the internal method which decodes them correctly, so no exception is raised, and the driver than hangs trying to read rows that aren't there. This tends to happen when calling stored procedures, as normal SELECTs won't have an error in this spot in the protocol unless an I/O error occurs. (Bug #32246)
Further fixes have been made to this bug in the event that a node is nonresponsive. Connector/J will now try a different random node instead of waiting for the node to recover before continuing. (Bug #31053)
DatabaseMetadata.getColumns() doesn't
return the correct column names if the connection character
isn't UTF-8. A bug in MySQL server compounded the issue, but was
fixed within the MySQL 5.0 release cycle. The fix includes
changes to all the sections of the code that access the server
metadata.
(Bug #20491)
Fixed ResultSetMetadata.getColumnName()
for result sets returned from
Statement.getGeneratedKeys() - it was
returning null instead of "GENERATED_KEY" as in 5.0.x.
New Features, Compared to the 5.0 Series of Connector/J
JDBC-4.0 standardized unwrapping to interfaces that include vendor extensions.
Support for JDBC-4.0 XML processing using JAXP interfaces to DOM, SAX and StAX.
JDBC-4.0 support for setting per-connection client information
(which can be viewed in the comments section of a query using
SHOW PROCESSLIST on a MySQL
server, or can be extended to support custom persistence of the
information using a public interface).
Functionality Added or Changed
Added autoSlowLog configuration property,
overrides slowQueryThreshold* properties,
driver determines slow queries by those that are slower than 5 *
stddev of the mean query time (outside the 96% percentile).
Bugs Fixed
When a connection is in read-only mode, queries that are wrapped in parentheses were incorrectly identified DML statements. (Bug #28256)
When calling setTimestamp on a prepared
statement, the timezone information stored in the calendar
object was ignored. This resulted in the incorrect
DATETIME information being stored. The
following example illustrates this:
Timestamp t = new Timestamp( cal.getTimeInMillis() ); ps.setTimestamp( N, t, cal );
(Bug #15604)
Only released internally.
Version 5.1.4 has no changelog entries.
New Features, Compared to the 5.0 Series of Connector/J
JDBC-4.0 standardized unwrapping to interfaces that include vendor extensions.
Support for JDBC-4.0 XML processing using JAXP interfaces to DOM, SAX and StAX.
JDBC-4.0 support for setting per-connection client information
(which can be viewed in the comments section of a query using
SHOW PROCESSLIST on a MySQL
server, or can be extended to support custom persistence of the
information using a public interface).
Functionality Added or Changed
Connector/J now connects using an initial character set of
utf-8 solely for the purpose of
authentication to permit user names or database names in any
character set to be used in the JDBC connection URL.
(Bug #29853)
Setting useBlobToStoreUTF8OutsideBMP to
true tells the driver to treat
[MEDIUM/LONG]BLOB columns as
[LONG]VARCHAR columns holding text encoded in
UTF-8 that has characters outside the BMP (4-byte encodings),
which MySQL server can't handle natively.
Set utf8OutsideBmpExcludedColumnNamePattern to
a regex so that column names matching the given regex will still
be treated as BLOBs The regex must follow the
patterns used for the java.util.regexpackage.
The default is to exclude no columns, and include all columns.
Set utf8OutsideBmpIncludedColumnNamePattern to
specify exclusion rules to
utf8OutsideBmpExcludedColumnNamePattern". The regex must follow
the patterns used for the java.util.regex
package.
New methods on com.mysql.jdbc.Statement:
setLocalInfileInputStream() and
getLocalInfileInputStream():
setLocalInfileInputStream() sets an
InputStream instance that will be used to
send data to the MySQL server for a
LOAD DATA LOCAL
INFILE statement rather than a
FileInputStream or
URLInputStream that represents the path
given as an argument to the statement.
This stream will be read to completion upon execution of a
LOAD DATA LOCAL
INFILE statement, and will automatically be closed
by the driver, so it needs to be reset before each call to
execute*() that would cause the MySQL
server to request data to fulfill the request for
LOAD DATA LOCAL
INFILE.
If this value is set to NULL, the driver
will revert to using a FileInputStream or
URLInputStream as required.
getLocalInfileInputStream() returns the
InputStream instance that will be used to
send data in response to a
LOAD DATA LOCAL
INFILE statement.
This method returns NULL if no such
stream has been set using
setLocalInfileInputStream().
Errors encountered during
Statement/PreparedStatement/CallableStatement.executeBatch()
when rewriteBatchStatements has been set to
true now return
BatchUpdateExceptions according to the
setting of continueBatchOnError.
If continueBatchOnError is set to
true, the update counts for the "chunk" that
were sent as one unit will all be set to
EXECUTE_FAILED, but the driver will attempt
to process the remainder of the batch. You can determine which
"chunk" failed by looking at the update counts returned in the
BatchUpdateException.
If continueBatchOnError is set to "false",
the update counts returned will contain all updates up-to and
including the failed "chunk", with all counts for the failed
"chunk" set to EXECUTE_FAILED.
Since MySQL doesn't return multiple error codes for
multiple-statements, or for multi-value
INSERT/REPLACE,
it is the application's responsibility to handle determining
which item(s) in the "chunk" actually failed.
Statement.setQueryTimeout()s now affect the
entire batch for batched statements, rather than the individual
statements that make up the batch.
JDBC-4.0 ease-of-development features including
auto-registration with the DriverManager
through the service provider mechanism, standardized Connection
validity checks and categorized SQLExceptions
based on recoverability/retry-ability and class of the
underlying error.
The driver will automatically adjust the server session variable
net_write_timeout when it
determines its been asked for a "streaming" result, and resets
it to the previous value when the result set has been consumed.
(The configuration property is named
netTimeoutForStreamingResults, with a unit of
seconds, the value '0' means the driver will not try and adjust
this value).
Added experimental support for statement "interceptors" through
the com.mysql.jdbc.StatementInterceptor
interface, examples are in
com/mysql/jdbc/interceptors. Implement this
interface to be placed "in between" query execution, so that it
can be influenced (currently experimental).
The data (and how it is stored) for ResultSet
rows are now behind an interface which enables us (in some
cases) to allocate less memory per row, in that for "streaming"
result sets, we re-use the packet used to read rows, since only
one row at a time is ever active.
The driver now picks appropriate internal row representation
(whole row in one buffer, or individual byte[]s for each column
value) depending on heuristics, including whether or not the row
has BLOB or
TEXT types and the overall
row-size. The threshold for row size that will cause the driver
to use a buffer rather than individual byte[]s is configured by
the configuration property
largeRowSizeThreshold, which has a default
value of 2KB.
Setting rewriteBatchedStatements to
true now causes CallableStatements with
batched arguments to be re-written in the form "CALL (...); CALL
(...); ..." to send the batch in as few client/server round
trips as possible.
Added two configuration parameters:
blobsAreStrings: Should the driver always
treat BLOBs as Strings. Added specifically to work around
dubious metadata returned by the server for GROUP
BY clauses. Defaults to false.
functionsNeverReturnBlobs: Should the
driver always treat data from functions returning
BLOBs as Strings. Added specifically to
work around dubious metadata returned by the server for
GROUP BY clauses. Defaults to false.
Bugs Fixed
CallableStatement.executeBatch() doesn't work
when connection property
noAccessToProcedureBodies has been set to
true.
The fix involves changing the behavior of
noAccessToProcedureBodies,in that the driver
will now report all parameters as IN
parameters but permit callers to call registerOutParameter() on
them without throwing an exception.
(Bug #28689)
NPE with null column values when
padCharsWithSpace is set to true.
(Bug #30851)
setObject(int, Object, int, int) delegate in
PreparedStatementWrapper delegates to wrong method.
(Bug #30892)
Closing a load-balanced connection would cause a
ClassCastException.
(Bug #29852)
DatabaseMetaData.getTypeInfo() for the types
DECIMAL and
NUMERIC will return a precision
of 254 for server versions older than 5.0.3, 64 for versions
5.0.3 to 5.0.5 and 65 for versions newer than 5.0.5.
(Bug #28972)
An ArithmeticException or
NullPointerException would be raised when the
batch had zero members and
rewriteBatchedStatements=true when
addBatch() was never called, or
executeBatch() was called immediately after
clearBatch().
(Bug #30550)
Collation on VARBINARY column
types would be misidentified. A fix has been added, but this fix
only works for MySQL server versions 5.0.25 and newer, since
earlier versions didn't consistently return correct metadata for
functions, and thus results from subqueries and functions were
indistinguishable from each other, leading to type-related bugs.
(Bug #30664)
Connection checker for JBoss didn't use same method parameters using reflection, causing connections to always seem "bad". (Bug #29106)
Schema objects with identifiers other than the connection
character aren't retrieved correctly in
ResultSetMetadata.
(Bug #27867)
Connection.getServerCharacterEncoding()
doesn't work for servers with version >= 4.1.
(Bug #27182)
DatabaseMetaData.getColumns() doesn't contain
SCOPE_* or
IS_AUTOINCREMENT columns.
(Bug #27915)
The automated SVN revisions in
DBMD.getDriverVersion(). The SVN revision of
the directory is now inserted into the version information
during the build.
(Bug #21116)
Specifying a "validation query" in your connection pool that starts with "/* ping */" _exactly_ will cause the driver to instead send a ping to the server and return a fake result set (much lighter weight), and when using a ReplicationConnection or a LoadBalancedConnection, will send the ping across all active connections.
This is a new Beta development release, fixing recently discovered bugs.
Functionality Added or Changed
Setting the configuration property
rewriteBatchedStatements to
true will now cause the driver to rewrite
batched prepared statements with more than 3 parameter sets in a
batch into multi-statements (separated by ";") if they are not
plain (that is, without SELECT or
ON DUPLICATE KEY UPDATE clauses)
INSERT or
REPLACE statements.
This is a new Alpha development release, adding new features and fixing recently discovered bugs.
Functionality Added or Changed
Incompatible Change:
Pulled vendor-extension methods of Connection
implementation out into an interface to support
java.sql.Wrapper functionality from
ConnectionPoolDataSource. The vendor
extensions are javadoc'd in the
com.mysql.jdbc.Connection interface.
For those looking further into the driver implementation, it is
not an API that is used for pluggability of implementations
inside our driver (which is why there are still references to
ConnectionImpl throughout the code).
We've also added server and client
prepareStatement() methods that cover all of
the variants in the JDBC API.
Connection.serverPrepare(String) has been
re-named to
Connection.serverPrepareStatement() for
consistency with
Connection.clientPrepareStatement().
Setting rewriteBatchedStatements to
true now causes
CallableStatements with batched arguments to
be re-written in the form CALL (...); CALL (...);
... to send the batch in as few client/server round
trips as possible.
See the sources (fully javadoc'd) for
com.mysql.jdbc.StatementInterceptor for more
details until we iron out the API and get it documented in the
manual.
Added experimental support for statement "interceptors" through
the com.mysql.jdbc.StatementInterceptor
interface, examples are in
com/mysql/jdbc/interceptors.
Implement this interface to be placed "in between" query execution, so that you can influence it. (currently experimental).
StatementInterceptors are "chainable" when
configured by the user, the results returned by the "current"
interceptor will be passed on to the next on in the chain, from
left-to-right order, as specified by the user in the JDBC
configuration property statementInterceptors.
Driver now picks appropriate internal row representation (whole
row in one buffer, or individual byte[]s for each column value)
depending on heuristics, including whether or not the row has
BLOB or
TEXT types and the overall
row-size. The threshold for row size that will cause the driver
to use a buffer rather than individual byte[]s is configured by
the configuration property
largeRowSizeThreshold, which has a default
value of 2KB.
Similar to Connection, we pulled out vendor
extensions to Statement into an interface
named com.mysql.Statement, and moved the
Statement class into
com.mysql.StatementImpl. The two methods
(javadoc'd in com.mysql.Statement are
enableStreamingResults(), which already
existed, and disableStreamingResults() which
sets the statement instance back to the fetch size and result
set type it had before
enableStreamingResults() was called.
The data (and how it is stored) for ResultSet
rows are now behind an interface which enables us (in some
cases) to allocate less memory per row, in that for "streaming"
result sets, we re-use the packet used to read rows, since only
one row at a time is ever active.
Externalized the descriptions of connection properties.
Made it possible to retrieve prepared statement parameter
bindings (to be used in
StatementInterceptors, primarily).
Row navigation now causes any streams/readers open on the result set to be closed, as in some cases we're reading directly from a shared network packet and it will be overwritten by the "next" row.
This is the first public alpha release of the current Connector/J 5.1 development branch, providing an insight to upcoming features. Although some of these are still under development, this release includes the following new features and changes (in comparison to the current Connector/J 5.0 production release):
Important change: Due to a number of issues with the use of server-side prepared statements, Connector/J 5.0.5 has disabled their use by default. The disabling of server-side prepared statements does not affect the operation of the connector in any way.
To enable server-side prepared statements you must add the following configuration property to your connector string:
useServerPrepStmts=true
The default value of this property is false
(that is, Connector/J does not use server-side prepared
statements).
The disabling of server-side prepared statements does not
affect the operation of the connector. However, if you use the
useTimezone=true connection option and use
client-side prepared statements (instead of server-side
prepared statements) you should also set
useSSPSCompatibleTimezoneShift=true.
Functionality Added or Changed
Added support for JDBC-4.0's Wrapper
interface.
com.mysql.jdbc.java6.rtjar: Full path to your
Java-6 rt.jar file
Added support for JDBC-4.0's client information. The backend
storage of information provided using
Connection.setClientInfo() and retrieved by
Connection.getClientInfo() is pluggable by
any class that implements the
com.mysql.jdbc.JDBC4ClientInfoProvider
interface and has a no-args constructor.
The implementation used by the driver is configured using the
clientInfoProvider configuration property
(with a default of value of
com.mysql.jdbc.JDBC4CommentClientInfoProvider,
an implementation which lists the client information as a
comment prepended to every query sent to the server).
This functionality is only available when using Java-6 or newer.
New feature—driver will automatically adjust session
variable net_write_timeout when
it determines it has been asked for a "streaming" result, and
resets it to the previous value when the result set has been
consumed. (configuration property is named
netTimeoutForStreamingResults value and has a
unit of seconds, the value 0 means the driver
will not try and adjust this value).
Re-worked Ant buildfile to build JDBC-4.0 classes separately, as well as support building under Eclipse (since Eclipse can't mix/match JDKs).
To build, you must set JAVA_HOME to
J2SDK-1.4.2 or Java-5, and set the following properties on your
Ant command line:
com.mysql.jdbc.java6.javac: Full path to
your Java-6 javac executable
com.mysql.jdbc.java6.rtjar: Full path to
your Java-6 rt.jar file
Added support for JDBC-4.0's SQLXML interfaces.
com.mysql.jdbc.java6.javac: Full path to your
Java-6 javac executable
Added support for JDBC-4.0's NCLOB, and
NCHAR/NVARCHAR
types.
Added support for JDBC-4.0 categorized
SQLExceptions.
Refactored CommunicationsException into a
JDBC-3.0 version, and a JDBC-4.0 version (which extends
SQLRecoverableException, now that it exists).
This change means that if you were catching
com.mysql.jdbc.CommunicationsException in
your applications instead of looking at the SQLState class of
08, and are moving to Java 6 (or newer),
you need to change your imports to that exception to be
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException,
as the old class will not be instantiated for communications
link-related errors under Java 6.
Functionality Added or Changed
Driver will now fall back to sane defaults for
max_allowed_packet and
net_buffer_length if the server
reports them incorrectly (and will log this situation at
WARN level, since it is actually an error
condition).
XAConnections now start in auto-commit mode (as per JDBC-4.0 specification clarification).
functionsNeverReturnBlobs: Should the driver
always treat data from functions returning
BLOBs as Strings. Added specifically to work
around dubious metadata returned by the server for
GROUP BY clauses. Defaults to false.
Added two configuration parameters:
blobsAreStrings: Should the driver always
treat BLOBs as Strings. Added specifically to work around
dubious metadata returned by the server for GROUP
BY clauses. Defaults to false.
functionsNeverReturnBlobs: Should the
driver always treat data from functions returning
BLOBs as Strings. Added specifically to
work around dubious metadata returned by the server for
GROUP BY clauses. Defaults to false.
blobsAreStrings: Should the driver always
treat BLOBs as Strings. Added specifically to work around
dubious metadata returned by the server for GROUP
BY clauses. Defaults to false.
Bugs Fixed
Connections established using URLs of the form
jdbc:mysql:loadbalance:// weren't doing
failover if they tried to connect to a MySQL server that was
down. The driver now attempts connections to the next "best"
(depending on the load balance strategy in use) server, and
continues to attempt connecting to the next "best" server every
250 milliseconds until one is found that is up and running or 5
minutes has passed.
If the driver gives up, it will throw the last-received
SQLException.
(Bug #31053)
CallableStatement.executeBatch() doesn't work
when connection property
noAccessToProcedureBodies has been set to
true.
The fix involves changing the behavior of
noAccessToProcedureBodies,in that the driver
will now report all parameters as IN
parameters but permit callers to call registerOutParameter() on
them without throwing an exception.
(Bug #28689)
NPE with null column values when
padCharsWithSpace is set to true.
(Bug #30851)
setObject(int, Object, int, int) delegate in
PreparedStatementWrapper delegates to wrong method.
(Bug #30892)
Closing a load-balanced connection would cause a
ClassCastException.
(Bug #29852)
DatabaseMetaData.getTypeInfo() for the types
DECIMAL and
NUMERIC will return a precision
of 254 for server versions older than 5.0.3, 64 for versions
5.0.3 to 5.0.5 and 65 for versions newer than 5.0.5.
(Bug #28972)
An ArithmeticException or
NullPointerException would be raised when the
batch had zero members and
rewriteBatchedStatements=true when
addBatch() was never called, or
executeBatch() was called immediately after
clearBatch().
(Bug #30550)
Collation on VARBINARY column
types would be misidentified. A fix has been added, but this fix
only works for MySQL server versions 5.0.25 and newer, since
earlier versions didn't consistently return correct metadata for
functions, and thus results from subqueries and functions were
indistinguishable from each other, leading to type-related bugs.
(Bug #30664)
Connection checker for JBoss didn't use same method parameters using reflection, causing connections to always seem "bad". (Bug #29106)
Cached metadata with
PreparedStatement.execute() throws
NullPointerException.
(Bug #27412)
UNSIGNED types not reported using
DBMD.getTypeInfo(), and capitalization of
type names is not consistent between
DBMD.getColumns(),
RSMD.getColumnTypeName() and
DBMD.getTypeInfo().
This fix also ensures that the precision of UNSIGNED
MEDIUMINT and UNSIGNED BIGINT is
reported correctly using DBMD.getColumns().
(Bug #27916)
When a connection is in read-only mode, queries that are wrapped in parentheses were incorrectly identified DML statements. (Bug #28256)
Schema objects with identifiers other than the connection
character aren't retrieved correctly in
ResultSetMetadata.
(Bug #27867)
Connection.getServerCharacterEncoding()
doesn't work for servers with version >= 4.1.
(Bug #27182)
DatabaseMetaData.getColumns() doesn't contain
SCOPE_* or
IS_AUTOINCREMENT columns.
(Bug #27915)
The automated SVN revisions in
DBMD.getDriverVersion(). The SVN revision of
the directory is now inserted into the version information
during the build.
(Bug #21116)
Specifying a "validation query" in your connection pool that starts with "/* ping */" _exactly_ will cause the driver to instead send a ping to the server and return a fake result set (much lighter weight), and when using a ReplicationConnection or a LoadBalancedConnection, will send the ping across all active connections.
Functionality Added or Changed
Added configuration property
useNanosForElapsedTime - for
profiling/debugging functionality that measures elapsed time,
should the driver try to use nanoseconds resolution if available
(requires JDK >= 1.5)?
If useNanosForElapsedTime is set to
true, and this property is set to "0" (or
left default), then elapsed times will still be measured in
nanoseconds (if possible), but the slow query threshold will
be converted from milliseconds to nanoseconds, and thus have
an upper bound of approximately 2000 milliseconds (as that
threshold is represented as an integer, not a long).
Added new debugging functionality - Setting configuration
property
includeInnodbStatusInDeadlockExceptions to
true will cause the driver to append the
output of SHOW
ENGINE INNODB STATUS to deadlock-related exceptions,
which will enumerate the current locks held inside InnoDB.
tcpTrafficClass - Should the driver set
traffic class or type-of-service fields? See the documentation
for java.net.Socket.setTrafficClass() for more information.
tcpSndBuf - Should the driver set SO_SND_BUF
to the given value? The default value of '0', means use the
platform default value for this property.
Setting the configuration parameter
useCursorFetch to true for
MySQL-5.0+ enables the use of cursors that enable Connector/J to
save memory by fetching result set rows in chunks (where the
chunk size is set by calling setFetchSize() on a Statement or
ResultSet) by using fully-materialized cursors on the server.
Added configuration properties to enable tuning of TCP/IP socket parameters:
tcpNoDelay - Should the driver set
SO_TCP_NODELAY (disabling the Nagle Algorithm, default
true)?
tcpKeepAlive - Should the driver set
SO_KEEPALIVE (default true)?
tcpRcvBuf - Should the driver set
SO_RCV_BUF to the given value? The default value of '0',
means use the platform default value for this property.
tcpSndBuf - Should the driver set
SO_SND_BUF to the given value? The default value of '0',
means use the platform default value for this property.
tcpTrafficClass - Should the driver set
traffic class or type-of-service fields? See the
documentation for java.net.Socket.setTrafficClass() for more
information.
Setting useDynamicCharsetInfo to
false now causes driver to use static lookups
for collations as well (makes
ResultSetMetadata.isCaseSensitive() much more efficient, which
leads to performance increase for ColdFusion, which calls this
method for every column on every table it sees, it appears).
tcpRcvBuf - Should the driver set SO_RCV_BUF
to the given value? The default value of '0', means use the
platform default value for this property.
Added configuration property
slowQueryThresholdNanos - if
useNanosForElapsedTime is set to
true, and this property is set to a nonzero
value the driver will use this threshold (in nanosecond units)
to determine if a query was slow, instead of using millisecond
units.
tcpNoDelay - Should the driver set
SO_TCP_NODELAY (disabling the Nagle Algorithm, default
true)?
Driver detects when it is running in a ColdFusion MX server
(tested with version 7), and uses the configuration bundle
coldFusion, which sets
useDynamicCharsetInfo to
false (see previous entry), and sets
useLocalSessionState and autoReconnect to
true.
Give more information in EOFExceptions thrown out of MysqlIO (how many bytes the driver expected to read, how many it actually read, say that communications with the server were unexpectedly lost).
tcpKeepAlive - Should the driver set
SO_KEEPALIVE (default true)?
The driver will now automatically set
useServerPrepStmts to true
when useCursorFetch has been set to
true, since the feature requires server-side
prepared statements to function.
Bugs Fixed
Parser in client-side prepared statements eats character following '/' if it is not a multi-line comment. (Bug #28851)
Parser in client-side prepared statements runs to end of statement, rather than end-of-line for '#' comments. Also added support for '--' single-line comments. (Bug #28956)
Don't send any file data in response to LOAD DATA LOCAL INFILE if the feature is disabled at the client side. This is to prevent a malicious server or man-in-the-middle from asking the client for data that the client is not expecting. Thanks to Jan Kneschke for discovering the exploit and Andrey "Poohie" Hristov, Konstantin Osipov and Sergei Golubchik for discussions about implications and possible fixes. (Bug #29605)
PreparedStatement.getMetaData() for statements containing leading one-line comments is not returned correctly.
As part of this fix, we also overhauled detection of DML for
executeQuery() and
SELECTs for
executeUpdate() in plain and prepared
statements to be aware of the same types of comments.
(Bug #28469)
Functionality Added or Changed
More intelligent initial packet sizes for the "shared" packets are used (512 bytes, rather than 16K), and initial packets used during handshake are now sized appropriately as to not require reallocation.
Driver will now use INSERT INTO ... VALUES
(DEFAULT)form of statement for updatable result sets
for ResultSet.insertRow(), rather than
pre-populating the insert row with values from
DatabaseMetaData.getColumns()(which results
in a SHOW FULL
COLUMNS on the server for every result set). If an
application requires access to the default values before
insertRow() has been called, the JDBC URL
should be configured with
populateInsertRowWithDefaultValues set to
true.
This fix specifically targets performance issues with ColdFusion and the fact that it seems to ask for updatable result sets no matter what the application does with them.
Fixed issue where a failed-over connection would let an
application call setReadOnly(false), when
that call should be ignored until the connection is reconnected
to a writable master unless failoverReadOnly
had been set to false.
com.mysql.jdbc.[NonRegistering]Driver now
understands URLs of the format
jdbc:mysql:replication:// and
jdbc:mysql:loadbalance:// which will create a
ReplicationConnection (exactly like when using
[NonRegistering]ReplicationDriver) and an
experimental load-balanced connection designed for use with SQL
nodes in a MySQL Cluster/NDB environment, respectively.
In an effort to simplify things, we're working on deprecating
multiple drivers, and instead specifying different core behavior
based upon JDBC URL prefixes, so watch for
[NonRegistering]ReplicationDriver to
eventually disappear, to be replaced with
com.mysql.jdbc[NonRegistering]Driver with the
new URL prefix.
random: The driver will pick a random host
for each request. This tends to work better than round-robin, as
the randomness will somewhat account for spreading loads where
requests vary in response time, while round-robin can sometimes
lead to overloaded nodes if there are variations in response
times across the workload.
Give better error message when "streaming" result sets, and the
connection gets clobbered because of exceeding
net_write_timeout on the
server.
New configuration property,
enableQueryTimeouts (default
true).
When enabled, query timeouts set with
Statement.setQueryTimeout() use a shared
java.util.Timer instance for scheduling. Even
if the timeout doesn't expire before the query is processed,
there will be memory used by the TimerTask
for the given timeout which won't be reclaimed until the time
the timeout would have expired if it hadn't been cancelled by
the driver. High-load environments might want to consider
disabling this functionality. (this configuration property is
part of the maxPerformance configuration
bundle).
Added configuration property
useDynamicCharsetInfo. If set to
false (the default), the driver will use a
per-connection cache of character set information queried from
the server when necessary, or when set to
true, use a built-in static mapping that is
more efficient, but isn't aware of custom character sets or
character sets implemented after the release of the JDBC driver.
This only affects the padCharsWithSpace
configuration property and the
ResultSetMetaData.getColumnDisplayWidth()
method.
When useLocalSessionState is set to
true and connected to a MySQL-5.0 or later
server, the JDBC driver will now determine whether an actual
commit or rollback
statement needs to be sent to the database when
Connection.commit() or
Connection.rollback() is called.
This is especially helpful for high-load situations with
connection pools that always call
Connection.rollback() on connection
check-in/check-out because it avoids a round-trip to the server.
Added configuration property
padCharsWithSpace (defaults to
false). If set to true,
and a result set column has the
CHAR type and the value does not
fill the amount of characters specified in the DDL for the
column, the driver will pad the remaining characters with space
(for ANSI compliance).
bestResponseTime: The driver will route the
request to the host that had the best response time for the
previous transaction.
Added an experimental load-balanced connection designed for use
with SQL nodes in a MySQL Cluster/NDB environment (This is not
for master-slave replication. For that, we suggest you look at
ReplicationConnection or
lbpool).
If the JDBC URL starts with
jdbc:mysql:loadbalance://host-1,host-2,...host-n,
the driver will create an implementation of
java.sql.Connection that load balances
requests across a series of MySQL JDBC connections to the given
hosts, where the balancing takes place after transaction commit.
Therefore, for this to work (at all), you must use transactions, even if only reading data.
Physical connections to the given hosts will not be created until needed.
The driver will invalidate connections that it detects have had communication errors when processing a request. A new connection to the problematic host will be attempted the next time it is selected by the load balancing algorithm.
There are two choices for load balancing algorithms, which may
be specified by the loadBalanceStrategy JDBC
URL configuration property:
random: The driver will pick a random
host for each request. This tends to work better than
round-robin, as the randomness will somewhat account for
spreading loads where requests vary in response time, while
round-robin can sometimes lead to overloaded nodes if there
are variations in response times across the workload.
bestResponseTime: The driver will route
the request to the host that had the best response time for
the previous transaction.
Bugs Fixed
When the configuration property
useCursorFetch was set to
true, sometimes server would return new, more
exact metadata during the execution of the server-side prepared
statement that enables this functionality, which the driver
ignored (using the original metadata returned during
prepare()), causing corrupt reading of data
due to type mismatch when the actual rows were returned.
(Bug #26173)
Whitespace surrounding storage/size specifiers in stored
procedure parameters declaration causes
NumberFormatException to be thrown when
calling stored procedure on JDK-1.5 or newer, as the Number
classes in JDK-1.5+ are whitespace intolerant.
(Bug #25624)
Connection.getTransactionIsolation() uses
"SHOW VARIABLES LIKE" which is very
inefficient on MySQL-5.0+ servers.
(Bug #27655)
ResultSet.get*() with a column index < 1
returns misleading error message.
(Bug #27317)
Fixed issue where calling getGeneratedKeys()
on a prepared statement after calling
execute() didn't always return the generated
keys (executeUpdate() worked fine however).
(Bug #27655)
BIT(> 1) is returned as
java.lang.String from
ResultSet.getObject() rather than
byte[].
(Bug #25328)
PreparedStatement is not closed in
BlobFromLocator.getBytes().
(Bug #26592)
Fast date/time parsing doesn't take into account
00:00:00 as a legal value.
(Bug #26789)
Client options not sent correctly when using SSL, leading to stored procedures not being able to return results. Thanks to Don Cohen for the bug report, testcase and patch. (Bug #25545)
More useful error messages are generated when the driver thinks a result set is not updatable. (Thanks to Ashley Martens for the patch). (Bug #28085)
CALL /* ... */
doesn't work.
As a side effect of this fix, you can now use some_proc()/*
*/ and # comments when preparing
statements using client-side prepared statement emulation.
If the comments happen to contain parameter markers
(?), they will be treated as belonging to the
comment (that is, not recognized) rather than being a parameter
of the statement.
The statement when sent to the server will contain the
comments as-is, they're not stripped during the process of
preparing the PreparedStatement or
CallableStatement.
(Bug #27400)
Comments in DDL of stored procedures/functions confuse procedure parser, and thus metadata about them can not be created, leading to inability to retrieve said metadata, or execute procedures that have certain comments in them. (Bug #26959)
Using ResultSet.get*() with a column index
less than 1 returns a misleading error message.
(Bug #27317)
CallableStatements with
OUT/INOUT parameters that are "binary"
(BLOB,
BIT,
(VAR)BINARY, JAVA_OBJECT)
have extra 7 bytes.
(Bug #25715)
Statement.setMaxRows() is not effective on
result sets materialized from cursors.
(Bug #25517)
Functionality Added or Changed
We've added a new configuration option
treatUtilDateAsTimestamp, which is
false by default, as (1) We already had
specific behavior to treat java.util.Date as a
java.sql.Timestamp because it is useful to many folks, and (2)
that behavior will very likely be required for drivers
JDBC-post-4.0.
Added configuration property
localSocketAddress, which is the host name or
IP address given to explicitly configure the interface that the
driver will bind the client side of the TCP/IP connection to
when connecting.
Fixed logging of XA commands sent to server, it is now
configurable using logXaCommands property
(defaults to false).
Usage Advisor now detects empty results sets and does not report on columns not referenced in those empty sets.
Improved speed of datetime parsing for
ResultSets that come from plain or nonserver-side prepared
statements. You can enable old implementation with
useFastDateParsing=false as a configuration
parameter.
Important change: Due to a number of issues with the use of server-side prepared statements, Connector/J 5.0.5 has disabled their use by default. The disabling of server-side prepared statements does not affect the operation of the connector in any way.
To enable server-side prepared statements, add the following configuration property to your connector string:
useServerPrepStmts=true
The default value of this property is false
(that is, Connector/J does not use server-side prepared
statements).
The rewriteBatchedStatements feature can now
be used with server-side prepared statements.
Usage Advisor will now issue warnings for result sets with large
numbers of rows. You can configure the trigger value by using
the resultSetSizeThreshold parameter, which
has a default value of 100.
Bugs Fixed
When using a server-side prepared statement the driver would send timestamps to the server using nanoseconds instead of milliseconds. (Bug #21438)
Connection property socketFactory wasn't
exposed using correctly named mutator/accessor, causing data
source implementations that use JavaBean naming conventions to
set properties to fail to set the property (and in the case of
SJAS, fail silently when trying to set this parameter).
(Bug #26326)
ParameterMetaData throws
NullPointerException when prepared SQL has a
syntax error. Added
generateSimpleParameterMetadata configuration
property, which when set to true will
generate metadata reflecting
VARCHAR for every parameter (the
default is false, which will cause an
exception to be thrown if no parameter metadata for the
statement is actually available).
(Bug #21267)
Connector/J now returns a better error message when server doesn't return enough information to determine stored procedure/function parameter types. (Bug #24065)
When using the rewriteBatchedStatements
connection option with
PreparedState.executeBatch() an internal
memory leak would occur.
(Bug #25073)
EscapeProcessor gets confused by multiple
backslashes. We now push the responsibility of syntax errors
back on to the server for most escape sequences.
(Bug #25399)
Specifying US-ASCII as the character set in a
connection to a MySQL 4.1 or newer server does not map
correctly.
(Bug #24840)
DatabaseMetaData.getSchemas() doesn't return
a TABLE_CATALOG column.
(Bug #23303)
INOUT parameters in
CallableStatements get doubly-escaped.
(Bug #25379)
Client-side prepared statement parser gets confused by in-line
comments /*...*/ and therefore cannot rewrite
batch statements or reliably detect the type of statements when
they are used.
(Bug #25025)
Results sets from UPDATE
statements that are part of multi-statement queries would cause
an SQLException error, "Result is from
UPDATE".
(Bug #25009)
When using server-side prepared statements and timestamp columns, value would be incorrectly populated (with nanoseconds, not microseconds). (Bug #21438)
Some exceptions thrown out of
StandardSocketFactory were needlessly
wrapped, obscuring their true cause, especially when using
socket timeouts.
(Bug #21480)
StringUtils.indexOfIgnoreCaseRespectQuotes()
isn't case-insensitive on the first character of the target.
This bug also affected
rewriteBatchedStatements functionality when
prepared statements did not use uppercase for the
VALUES clause.
(Bug #25047)
Using DatabaseMetaData.getSQLKeywords() does
not return a all of the of the reserved keywords for the current
MySQL version. Current implementation returns the list of
reserved words for MySQL 5.1, and does not distinguish between
versions.
(Bug #24794)
A query execution which timed out did not always throw a
MySQLTimeoutException.
(Bug #25836)
A connection error would occur when connecting to a MySQL server
with certain character sets. Some collations/character sets
reported as "unknown" (specifically cias
variants of existing character sets), and inability to override
the detected server character set.
(Bug #23645)
Using setFetchSize() breaks prepared
SHOW and other commands.
(Bug #24360)
Fixed issue where field-level for metadata from
DatabaseMetaData when using
INFORMATION_SCHEMA didn't have references to
current connections, sometimes leading to Null Pointer
Exceptions (NPEs) when introspecting them using
ResultSetMetaData.
(Bug #25073)
Using DATETIME columns would
result in time shifts when useServerPrepStmts
was true. This occurred due to different behavior when using
client-side compared to server-side prepared statements and the
useJDBCCompliantTimezoneShift option. This is
now fixed if moving from server-side prepared statements to
client-side prepared statements by setting
useSSPSCompatibleTimezoneShift to
true, as the driver can't tell if this is a
new deployment that never used server-side prepared statements,
or if it is an existing deployment that is switching to
client-side prepared statements from server-side prepared
statements.
(Bug #24344)
When using a JDBC connection URL that is malformed, the
NonRegisteringDriver.getPropertyInfo method
will throw a Null Pointer Exception (NPE).
(Bug #22628)
Storing a java.util.Date object in a
BLOB column would not be
serialized correctly during setObject.
(Bug #25787)
Inconsistency between getSchemas and
INFORMATION_SCHEMA.
(Bug #23304)
Calendars and timezones are now lazily instantiated when required. (Bug #24351)
Timer instance used for
Statement.setQueryTimeout() created
per-connection, rather than per-VM, causing memory leak.
(Bug #25514)
Calling Statement.cancel() could result in a
Null Pointer Exception (NPE).
(Bug #24721)
Fixed an issue where XADataSources couldn't
be bound into JNDI, as the DataSourceFactory
didn't know how to create instances of them.
Other Changes
When using cached metadata, skip field-level metadata packets
coming from the server, rather than reading them and discarding
them without creating com.mysql.jdbc.Field
instances.
Use a java.util.TreeMap to map column names
to ordinal indexes for ResultSet.findColumn()
instead of a HashMap. This enables us to have case-insensitive
lookups (required by the JDBC specification) without resorting
to the many transient object instances needed to support this
requirement with a normal HashMap with either
case-adjusted keys, or case-insensitive keys. (In the worst case
scenario for lookups of a 1000 column result set, TreeMaps are
about half as fast wall-clock time as a HashMap, however in
normal applications their use gives many orders of magnitude
reduction in transient object instance creation which pays off
later for CPU usage in garbage collection).
Fixed cases where ServerPreparedStatements
weren't using cached metadata when
cacheResultSetMetadata=true was used.
Take localSocketAddress property into account
when creating instances of
CommunicationsException when the underlying
exception is a java.net.BindException, so
that a friendlier error message is given with a little internal
diagnostics.
Fixed some Null Pointer Exceptions (NPEs) when cached metadata
was used with UpdatableResultSets.
When extracting foreign key information from
SHOW CREATE TABLE in
DatabaseMetaData, ignore exceptions relating
to tables being missing (which could happen for cross-reference
or imported-key requests, as the list of tables is generated
first, then iterated).
Reverted back to internal character conversion routines for single-byte character sets, as the ones internal to the JVM are using much more CPU time than our internal implementation.
Changed cached result set metadata (when using
cacheResultSetMetadata=true) to be cached
per-connection rather than per-statement as previously
implemented.
Throw exceptions encountered during timeout to thread calling
Statement.execute*(), rather than
RuntimeException.
Re-worked stored procedure parameter parser to be more robust.
Driver no longer requires BEGIN in stored
procedure definition, but does have requirement that if a stored
function begins with a label directly after the "returns"
clause, that the label is not a quoted identifier.
Performance enhancement of initial character set configuration, driver will only send commands required to configure connection character set session variables if the current values on the server do not match what is required.
Avoid static synchronized code in JVM class libraries for dealing with default timezones.
Bugs Fixed
Driver issues truncation on write exception when it shouldn't (due to sending big decimal incorrectly to server with server-side prepared statement). (Bug #22290)
Newlines causing whitespace to span confuse procedure parser when getting parameter metadata for stored procedures. (Bug #22024)
Driver was using milliseconds for Statement.setQueryTimeout() when specification says argument is to be in seconds. (Bug #22359)
Added new _ci collations to CharsetMapping - utf8_unicode_ci not working. (Bug #22456)
Workaround for server crash when calling stored procedures using a server-side prepared statement (driver now detects prepare(stored procedure) and substitutes client-side prepared statement). (Bug #22297)
When using information_schema for metadata, COLUMN_SIZE for getColumns() is not clamped to range of java.lang.Integer as is the case when not using information_schema, thus leading to a truncation exception that isn't present when not using information_schema. (Bug #21544)
DBMD.getColumns() does not return expected COLUMN_SIZE for the SET type, now returns length of largest possible set disregarding whitespace or the "," delimiters to be consistent with the ODBC driver. (Bug #22613)
Column names don't match metadata in cases where server doesn't
return original column names (column functions) thus breaking
compatibility with applications that expect 1-to-1 mappings
between findColumn() and
rsmd.getColumnName(), usually manifests
itself as "Can't find column ('')" exceptions.
(Bug #21379)
Driver now supports {call sp} (without "()"
if procedure has no arguments).
DatabaseMetaData correctly reports true for
supportsCatalog*() methods.
Fixed configuration property
jdbcCompliantTruncation was not being used
for reads of result set values.
Driver now sends numeric 1 or 0 for client-prepared statement
setBoolean() calls instead of '1' or '0'.
Functionality Added or Changed
Added configuration option
noAccessToProcedureBodies which will cause
the driver to create basic parameter metadata for
CallableStatements when the user does not
have access to procedure bodies using SHOW
CREATE PROCEDURE or selecting from
mysql.proc instead of throwing an exception.
The default value for this option is false
Bugs Fixed
Fixed Statement.cancel() causes
NullPointerException if underlying connection
has been closed due to server failure.
(Bug #20650)
If the connection to the server has been closed due to a server
failure, then the cleanup process will call
Statement.cancel(), triggering a
NullPointerException, even though there is no
active connection.
(Bug #20650)
Bugs Fixed
MysqlXaConnection.recover(int flags) now
permits combinations of
XAResource.TMSTARTRSCAN and
TMENDRSCAN. To simulate the
“scanning” nature of the interface, we return all
prepared XIDs for TMSTARTRSCAN, and no new
XIDs for calls with TMNOFLAGS, or
TMENDRSCAN when not in combination with
TMSTARTRSCAN. This change was made for API
compliance, as well as integration with IBM WebSphere's
transaction manager.
(Bug #20242)
Fixed MysqlValidConnectionChecker for JBoss
doesn't work with MySQLXADataSources.
(Bug #20242)
Added connection/datasource property
pinGlobalTxToPhysicalConnection (defaults to
false). When set to true,
when using XAConnections, the driver ensures
that operations on a given XID are always routed to the same
physical connection. This enables the
XAConnection to support XA START ...
JOIN after
XA END
has been called, and is also a workaround for transaction
managers that don't maintain thread affinity for a global
transaction (most either always maintain thread affinity, or
have it as a configuration option).
(Bug #20242)
Fixed driver fails on non-ASCII platforms. The driver was
assuming that the platform character set would be a superset of
MySQL's latin1 when doing the handshake for
authentication, and when reading error messages. We now use
Cp1252 for all strings sent to the server during the handshake
phase, and a hard-coded mapping of the
language system variable to the
character set that is used for error messages.
(Bug #18086)
Fixed can't use XAConnection for local
transactions when no global transaction is in progress.
(Bug #17401)
Better caching of character set converters (per-connection) to remove a bottleneck for multibyte character sets. (Bug #20242)
Fixed ConnectionProperties (and thus some
subclasses) are not serializable, even though some J2EE
containers expect them to be.
(Bug #19169)
Not released due to a packaging error
Version 5.0.1 has no changelog entries.
Bugs Fixed
Added support for Connector/MXJ integration using url
subprotocol jdbc:mysql:mxj://....
(Bug #14729)
Idle timeouts cause XAConnections to whine
about rolling themselves back.
(Bug #14729)
When fix for Bug #14562 was merged from 3.1.12, added
functionality for CallableStatement's
parameter metadata to return correct information for
.getParameterClassName().
(Bug #14729)
Added service-provider entry to
META-INF/services/java.sql.Driver for
JDBC-4.0 support.
(Bug #14729)
Fuller synchronization of Connection to avoid
deadlocks when using multithreaded frameworks that multithread a
single connection (usually not recommended, but the JDBC spec
permits it anyways), part of fix to Bug #14972).
(Bug #14729)
Moved all SQLException constructor usage to a
factory in SQLError (ground-work for JDBC-4.0
SQLState-based exception classes).
(Bug #14729)
Removed Java5-specific calls to BigDecimal
constructor (when result set value is '',
(int)0 was being used as an argument
indirectly using method return value. This signature doesn't
exist prior to Java5.)
(Bug #14729)
Implementation of Statement.cancel() and
Statement.setQueryTimeout(). Both require
MySQL-5.0.0 or newer server, require a separate connection to
issue the KILL
QUERY statement, and in the case of
setQueryTimeout() creates an additional
thread to handle the timeout functionality.
Note: Failures to cancel the statement for
setQueryTimeout() may manifest themselves as
RuntimeExceptions rather than failing
silently, as there is currently no way to unblock the thread
that is executing the query being cancelled due to timeout
expiration and have it throw the exception instead.
(Bug #14729)
Return "[VAR]BINARY" for
RSMD.getColumnTypeName() when that is
actually the type, and it can be distinguished (MySQL-4.1 and
newer).
(Bug #14729)
Add one level of indirection of internal representation of
CallableStatement parameter metadata to avoid
class not found issues on JDK-1.3 for
ParameterMetadata interface (which doesn't
exist prior to JDBC-3.0).
PreparedStatement.setString() didn't work
correctly when sql_mode on
server contained
NO_BACKSLASH_ESCAPES and no
characters that needed escaping were present in the string.
Setting useJDBCCompliantTimezoneShift=true
(it is not the default) causes the driver to use GMT for
all
TIMESTAMP/DATETIME
time zones, and the current VM time zone for any other type that
refers to time zones. This feature can not be used when
useTimezone=true to convert between server
and client time zones.
Return original column name for
RSMD.getColumnName() if the column was
aliased, alias name for .getColumnLabel() (if
aliased), and original table name for
.getTableName(). Note this only works for
MySQL-4.1 and newer, as older servers don't make this
information available to clients.
Moved -bin-g.jar file into separate
debug subdirectory to avoid confusion.
XADataSource implemented (ported from 3.2
branch which won't be released as a product). Use
com.mysql.jdbc.jdbc2.optional.MysqlXADataSource
as your datasource class name in your application server to
utilize XA transactions in MySQL-5.0.10 and newer.
Do not permit .setAutoCommit(true), or
.commit() or .rollback()
on an XA-managed connection as per the JDBC specification.
If the connection useTimezone is set to
true, then also respect time zone conversions
in escape-processed string literals (for example, "{ts
...}" and "{t ...}").
Added unit tests for XADatasource, as well as
friendlier exceptions for XA failures compared to the "stock"
XAException (which has no messages).
Attempt detection of the MySQL type
BINARY (it is an alias, so this
isn't always reliable), and use the
java.sql.Types.BINARY type mapping for it.
Important change: Due to a number of issues with the use of server-side prepared statements, Connector/J 5.0.5 has disabled their use by default. The disabling of server-side prepared statements does not affect the operation of the connector in any way.
To enable server-side prepared statements you must add the following configuration property to your connector string:
useServerPrepStmts=true
The default value of this property is false
(that is, Connector/J does not use server-side prepared
statements).
Bugs Fixed
Specifying US-ASCII as the character set in a
connection to a MySQL 4.1 or newer server does not map
correctly.
(Bug #24840)
Bugs Fixed
Check and store value for continueBatchOnError property in constructor of Statements, rather than when executing batches, so that Connections closed out from underneath statements don't cause NullPointerExceptions when it is required to check this property. (Bug #22290)
Fixed Updatable result set that contains a BIT column fails when server-side prepared statements are used. (Bug #20485)
Escape of quotation marks in client-side prepared statements parsing not respected. Patch covers more than bug report, including NO_BACKSLASH_ESCAPES being set, and stacked quote characters forms of escaping (that is, '' or ""). (Bug #20888)
Driver now sends numeric 1 or 0 for client-prepared statement setBoolean() calls instead of '1' or '0'. (Bug #22290)
Fixed bug where driver would not advance to next host if roundRobinLoadBalance=true and the last host in the list is down. (Bug #22290)
Driver issues truncation on write exception when it shouldn't (due to sending big decimal incorrectly to server with server-side prepared statement). (Bug #22290)
ResultSet.getSomeInteger() doesn't work for BIT(>1). (Bug #21062)
Fixed bug when calling stored functions, where parameters weren't numbered correctly (first parameter is now the return value, subsequent parameters if specified start at index "2"). (Bug #22290)
Removed logger autodetection altogether, must now specify logger explicitly if you want to use a logger other than one that logs to STDERR. (Bug #21207)
Fixed can't pool server-side prepared statements, exception raised when re-using them. (Bug #20687)
DDriver throws NPE when tracing prepared statements that have been closed (in asSQL()). (Bug #21207)
Fixed ResultSet.getShort() for UNSIGNED TINYINT returns incorrect values when using server-side prepared statements. (Bug #20306)
ReplicationDriver does not always round-robin load balance depending on URL used for slaves list. (Bug #19993)
DatabaseMetaData.getTables() or
getColumns() with a bad catalog parameter
threw an exception rather than return an empty result set (as
required by the specification).
(Bug #18258)
Fixed memory leak with profileSQL=true. (Bug #16987)
Connection fails to localhost when using timeout and IPv6 is configured. (Bug #19726)
Fixed updatable result set throws ClassCastException when there is row data and moveToInsertRow() is called. (Bug #20479)
Fixed calling toString() on ResultSetMetaData for driver-generated (that is, from DatabaseMetaData method calls, or from getGeneratedKeys()) result sets would raise a NullPointerException. (Bug #19993)
Fixed NullPointerException in MysqlDataSourceFactory due to Reference containing RefAddrs with null content. (Bug #16791)
ResultSet.getFloatFromString() can't retrieve values near Float.MIN/MAX_VALUE. (Bug #18880)
Bugs Fixed
Added performance feature, re-writing of batched executes for
Statement.executeBatch() (for all DML
statements) and
PreparedStatement.executeBatch() (for INSERTs
with VALUE clauses only). Enable by using
"rewriteBatchedStatements=true" in your JDBC URL.
(Bug #18041)
DBMD.getColumns() returns wrong type for
BIT.
(Bug #15854)
PreparedStatement.setObject() serializes
BigInteger as object, rather than sending as
numeric value (and is thus not complementary to
.getObject() on an UNSIGNED
LONG type).
(Bug #15383)
Fixed aliased column names where length of name > 251 are corrupted. (Bug #18554)
Exception thrown for new decimal type when using updatable result sets. (Bug #14609)
Improved performance of retrieving
BigDecimal, Time,
Timestamp and Date values
from server-side prepared statements by creating fewer
short-lived instances of Strings when the
native type is not an exact match for the requested type.
(Bug #18496)
Fixed calling clearParameters() on a closed
prepared statement causes NPE.
(Bug #17587)
Driver now aware of fix for BIT
type metadata that went into MySQL-5.0.21 for server not
reporting length consistently .
(Bug #13601)
No "dos" character set in MySQL > 4.1.0. (Bug #15544)
Map "latin1" on MySQL server to CP1252 for MySQL > 4.1.0. (Bug #17587)
Fixed
CallableStatement.registerOutParameter() not
working when some parameters pre-populated. Still waiting for
feedback from JDBC experts group to determine what correct
parameter count from getMetaData() should be,
however.
(Bug #17898)
Fixed ResultSet.wasNull() not always reset
correctly for booleans when done using conversion for
server-side prepared statements.
(Bug #17450)
Added support for Apache Commons logging, use "com.mysql.jdbc.log.CommonsLogger" as the value for the "logger" configuration property. (Bug #13469)
Fixed ResultSet.wasNull() returns incorrect
value when extracting native string from server-side prepared
statement generated result set.
(Bug #19282)
Fixed updatable result set doesn't return
AUTO_INCREMENT values for
insertRow() when multiple column primary keys
are used. (the driver was checking for the existence of
single-column primary keys and an autoincrement value > 0
instead of a straightforward
isAutoIncrement() check).
(Bug #16841)
Fixed invalid classname returned for
ResultSetMetaData.getColumnClassName() for
BIGINT type.
(Bug #19282)
INOUT parameter does not store
IN value.
(Bug #15464)
Fixed issue with ReplicationConnection
incorrectly copying state, doesn't transfer connection context
correctly when transitioning between the same read-only states.
(Bug #15570)
Fixed case where driver wasn't reading server status correctly when fetching server-side prepared statement rows, which in some cases could cause warning counts to be off, or multiple result sets to not be read off the wire. (Bug #19282)
Fixed PreparedStatement.setObject(int, Object,
int) doesn't respect scale of BigDecimals.
(Bug #19615)
Fixed driver trying to call methods that don't exist on older and newer versions of Log4j. The fix is not trying to auto-detect presence of log4j, too many different incompatible versions out there in the wild to do this reliably.
If you relied on autodetection before, you will need to add "logger=com.mysql.jdbc.log.Log4JLogger" to your JDBC URL to enable Log4J usage, or alternatively use the new "CommonsLogger" class to take care of this. (Bug #13469)
Fixed Statement.getGeneratedKeys() throws
NullPointerException when no query has been
processed.
(Bug #17099)
lib-nodist directory missing from package
breaks out-of-box build.
(Bug #15676)
Added additional accessor and mutator methods on ConnectionProperties so that DataSource users can use same naming as regular URL properties. (Bug #17587)
LogFactory now prepends com.mysql.jdbc.log to
the log class name if it cannot be found as specified. This
enables you to use “short names” for the built-in
log factories, for example,
logger=CommonsLogger instead of
logger=com.mysql.jdbc.log.CommonsLogger.
(Bug #13469)
Fixed data truncation and getWarnings() only
returns last warning in set.
(Bug #18740)
Fixed issue where server-side prepared statements don't cause truncation exceptions to be thrown when truncation happens. (Bug #18041)
Fixed issue where driver was unable to initialize character set
mapping tables. Removed reliance on
.properties files to hold this information,
as it turns out to be too problematic to code around class
loader hierarchies that change depending on how an application
is deployed. Moved information back into the
CharsetMapping class.
(Bug #14938)
ResultSet.getShort() for UNSIGNED
TINYINT returned wrong values.
(Bug #11874)
Bugs Fixed
Driver incorrectly closes streams passed as arguments to
PreparedStatements. Reverts to legacy
behavior by setting the JDBC configuration property
autoClosePStmtStreams to
true (also included in the 3-0-Compat
configuration “bundle”).
(Bug #15024)
storesMixedCaseIdentifiers() returns
false
(Bug #14562)
storesLowerCaseIdentifiers() returns
true
(Bug #14562)
Deadlock while closing server-side prepared statements from multiple threads sharing one connection. (Bug #14972)
OpenOffice expects
DBMD.supportsIntegrityEnhancementFacility()
to return true if foreign keys are supported
by the datasource, even though this method also covers support
for check constraints, which MySQL doesn't
have. Setting the configuration property
overrideSupportsIntegrityEnhancementFacility
to true causes the driver to return
true for this method.
(Bug #12975)
storesMixedCaseQuotedIdentifiers() returns
false
(Bug #14562)
storesMixedCaseQuotedIdentifiers() returns
true
(Bug #14562)
maxQuerySizeToLog is not respected. Added
logging of bound values for execute() phase
of server-side prepared statements when
profileSQL=true as well.
(Bug #13048)
Process escape tokens in
Connection.prepareStatement(...). You can
disable this behavior by setting the JDBC URL configuration
property processEscapeCodesForPrepStmts to
false.
(Bug #15141)
DatabaseMetaData.getColumns() doesn't return
TABLE_NAME correctly.
(Bug #14815)
If lower_case_table_names=0 (on server):
storesLowerCaseIdentifiers() returns
false
storesLowerCaseQuotedIdentifiers()
returns false
storesMixedCaseIdentifiers() returns
true
storesMixedCaseQuotedIdentifiers()
returns true
storesUpperCaseIdentifiers() returns
false
storesUpperCaseQuotedIdentifiers()
returns true
(Bug #14562)
storesUpperCaseIdentifiers() returns
false
(Bug #14562)
storesUpperCaseQuotedIdentifiers() returns
true
(Bug #14562)
If lower_case_table_names=1 (on server):
storesLowerCaseIdentifiers() returns
true
storesLowerCaseQuotedIdentifiers()
returns true
storesMixedCaseIdentifiers() returns
false
storesMixedCaseQuotedIdentifiers()
returns false
storesUpperCaseIdentifiers() returns
false
storesUpperCaseQuotedIdentifiers()
returns true
(Bug #14562)
Extraneous sleep on autoReconnect.
(Bug #13775)
storesLowerCaseQuotedIdentifiers() returns
true
(Bug #14562)
Fixed DatabaseMetaData.stores*Identifiers():
If lower_case_table_names=0 (on server):
storesLowerCaseIdentifiers() returns
false
storesLowerCaseQuotedIdentifiers()
returns false
storesMixedCaseIdentifiers() returns
true
storesMixedCaseQuotedIdentifiers()
returns true
storesUpperCaseIdentifiers() returns
false
storesUpperCaseQuotedIdentifiers()
returns true
If lower_case_table_names=1 (on server):
storesLowerCaseIdentifiers() returns
true
storesLowerCaseQuotedIdentifiers()
returns true
storesMixedCaseIdentifiers() returns
false
storesMixedCaseQuotedIdentifiers()
returns false
storesUpperCaseIdentifiers() returns
false
storesUpperCaseQuotedIdentifiers()
returns true
(Bug #14562)
Reconnect during middle of executeBatch()
should not occur if autoReconnect is enabled.
(Bug #13255)
storesMixedCaseIdentifiers() returns
true
(Bug #14562)
Usage advisor complains about unreferenced columns, even though they've been referenced. (Bug #15065)
storesLowerCaseQuotedIdentifiers() returns
false
(Bug #14562)
Java type conversion may be incorrect for
MEDIUMINT.
(Bug #14562)
Added com.mysql.jdbc.testsuite.url.default
system property to set default JDBC url for testsuite (to speed
up bug resolution when I'm working in Eclipse).
(Bug #12975)
Unable to initialize character set mapping tables (due to J2EE classloader differences). (Bug #14938)
storesLowerCaseIdentifiers() returns
false
(Bug #14562)
Escape processor replaces quote character in quoted string with string delimiter. (Bug #14909)
Added configuration property
useGmtMillisForDatetimes which when set to
true causes
ResultSet.getDate(),
.getTimestamp() to return correct
millis-since GMT when .getTime() is called on
the return value (currently default is false
for legacy behavior).
(Bug #14562)
logSlowQueries should give better info.
(Bug #12230)
Don't increase timeout for failover/reconnect. (Bug #6577)
Fall back to platform-encoding for
URLDecoder.decode() when parsing driver URL
properties if the platform doesn't have a two-argument version
of this method.
Do not permit executeBatch() for
CallableStatements with registered
OUT/INOUT parameters (JDBC
compliance).
Fixed client-side prepared statement bug with embedded
? characters inside quoted identifiers (it
was recognized as a placeholder, when it was not).
Bugs Fixed
getExportedKeys()
(Bug #12541)
Specifying a catalog works as stated in the API docs. (Bug #12541)
Specifying NULL means that catalog will not
be used to filter the results (thus all databases will be
searched), unless you've set
nullCatalogMeansCurrent=true in your JDBC URL
properties.
(Bug #12541)
Tokenizer for = in URL properties was causing
sessionVariables=.... to be parameterized
incorrectly.
(Bug #12753)
getIndexInfo()
(Bug #12541)
getProcedures() (and thus indirectly
getProcedureColumns())
(Bug #12541)
getImportedKeys()
(Bug #12541)
Specifying "" means “current”
catalog, even though this isn't quite JDBC spec compliant, it is
there for legacy users.
(Bug #12541)
getCrossReference()
(Bug #12541)
The configuration property sessionVariables
now permits you to specify variables that start with the
“@” sign.
(Bug #13453)
Added Connection.isMasterConnection() for
clients to be able to determine if a multi-host master/slave
connection is connected to the first host in the list.
(Bug #12541)
Workaround for Bug #13374:
ResultSet.getStatement() on closed result set
returns NULL (as per JDBC 4.0 spec, but not
backward-compatible). Set the connection property
retainStatementAfterResultSetClose to
true to be able to retrieve a
ResultSet's statement after the
ResultSet has been closed using
.getStatement() (the default is
false, to be JDBC-compliant and to reduce the
chance that code using JDBC leaks Statement
instances).
(Bug #13277)
java.sql.Types.OTHER returned for
BINARY and
VARBINARY columns when using
DatabaseMetaData.getColumns().
(Bug #12970)
URL configuration parameters do not permit
“&” or
“=” in their values. The JDBC
driver now parses configuration parameters as if they are
encoded using the application/x-www-form-urlencoded format as
specified by java.net.URLDecoder
(http://java.sun.com/j2se/1.5.0/docs/api/java/net/URLDecoder.html).
If the “%” character is present
in a configuration property, it must now be represented as
%25, which is the encoded form of
“%” when using
application/x-www-form-urlencoded encoding.
(Bug #13453)
getColumns()
(Bug #12541)
Handling of catalog argument in
DatabaseMetaData.getIndexInfo(), which also
means changes to the following methods in
DatabaseMetaData:
getBestRowIdentifier()
getColumns()
getCrossReference()
getExportedKeys()
getImportedKeys()
getIndexInfo()
getPrimaryKeys()
getProcedures() (and thus indirectly
getProcedureColumns())
getTables()
The catalog argument in all of these methods
now behaves in the following way:
Specifying NULL means that catalog will
not be used to filter the results (thus all databases will
be searched), unless you've set
nullCatalogMeansCurrent=true in your JDBC
URL properties.
Specifying "" means
“current” catalog, even though this isn't quite
JDBC spec compliant, it is there for legacy users.
Specifying a catalog works as stated in the API docs.
Made Connection.clientPrepare() available
from “wrapped” connections in the
jdbc2.optional package (connections built
by ConnectionPoolDataSource instances).
(Bug #12541)
getBestRowIdentifier()
(Bug #12541)
Made Connection.clientPrepare() available
from “wrapped” connections in the
jdbc2.optional package (connections built by
ConnectionPoolDataSource instances).
(Bug #12541)
ServerPreparedStatement.getBinding() now
checks if the statement is closed before attempting to reference
the list of parameter bindings, to avoid throwing a
NullPointerException.
(Bug #12970)
ResultSetMetaData from
Statement.getGeneratedKeys() caused a
NullPointerException to be thrown whenever a
method that required a connection reference was called.
(Bug #13277)
cp1251 incorrectly mapped to
win1251 for servers newer than 4.0.x.
(Bug #12752)
When gatherPerfMetrics is enabled for servers
older than 4.1.0, a NullPointerException is
thrown from the constructor of ResultSet if
the query doesn't use any tables.
(Bug #13043)
Backport of VAR[BINARY|CHAR] [BINARY] types
detection from 5.0 branch.
(Bug #13277)
getTables()
(Bug #12541)
Fixed NullPointerException when converting
catalog parameter in many
DatabaseMetaDataMethods to
byte[]s (for the result set) when the
parameter is null. (null
is not technically permitted by the JDBC specification, but we
have historically permitted it).
(Bug #13277)
Backport of Field class,
ResultSetMetaData.getColumnClassName(), and
ResultSet.getObject(int) changes from 5.0
branch to fix behavior surrounding VARCHAR
BINARY/VARBINARY and
related types.
(Bug #13277)
Read response in MysqlIO.sendFileToServer(),
even if the local file can't be opened, otherwise next query
issued will fail, because it is reading the response to the
empty LOAD DATA
INFILE packet sent to the server.
(Bug #13277)
Connection.prepareCall() is database name
case-sensitive (on Windows systems).
(Bug #12417)
getPrimaryKeys()
(Bug #12541)
Geometry types not handled with server-side prepared statements. (Bug #12104)
explainSlowQueries hangs with server-side
prepared statements.
(Bug #12229)
Pstmt.setObject(...., Types.BOOLEAN) throws
exception.
(Bug #11798)
Reworked Field class,
*Buffer, and MysqlIO to be
aware of field lengths >
Integer.MAX_VALUE.
(Bug #11498)
Foreign key information that is quoted is parsed incorrectly
when DatabaseMetaData methods use that
information.
(Bug #11781)
Fixed regression caused by fix for Bug #11552 that caused driver to return incorrect values for unsigned integers when those integers where within the range of the positive signed type. (Bug #11663)
Escape tokenizer doesn't respect stacked single quotation marks for escapes. (Bug #11797)
Escape processor didn't honor strings demarcated with double quotation marks. (Bug #11498)
maxPerformance.properties mis-spells
“elideSetAutoCommits”.
(Bug #11976)
Moved source code to Subversion repository. (Bug #11663)
The sendBlobChunkSize property is now clamped
to max_allowed_packet with
consideration of stream buffer size and packet headers to avoid
PacketTooBigExceptions when
max_allowed_packet is similar
in size to the default sendBlobChunkSize
which is 1M.
(Bug #11781)
Statement.getWarnings() fails with NPE if
statement has been closed.
(Bug #10630)
DBMD.storesLower/Mixed/UpperIdentifiers()
reports incorrect values for servers deployed on Windows.
(Bug #11575)
ResultSet.moveToCurrentRow() fails to work
when preceded by a call to
ResultSet.moveToInsertRow().
(Bug #11190)
VARBINARY data corrupted when
using server-side prepared statements and
.setBytes().
(Bug #11115)
Only get char[] from SQL in
PreparedStatement.ParseInfo() when needed.
(Bug #10630)
Incorrect generation of testcase scripts for server-side prepared statements. (Bug #11663)
GEOMETRY type not recognized when using
server-side prepared statements.
(Bug #11797)
CallableStatement.clearParameters() now
clears resources associated with
INOUT/OUTPUT parameters as
well as INPUT parameters.
(Bug #11781)
StringUtils.getBytes() doesn't work when
using multi-byte character encodings and a length in
characters is specified.
(Bug #11614)
Fixed statements generated for testcases missing
; for “plain” statements.
(Bug #11629)
ReplicationConnection won't switch to slave,
throws “Catalog can't be null” exception.
(Bug #11879)
Spurious ! on console when character encoding
is utf8.
(Bug #11629)
Properties shared between master and slave with replication connection. (Bug #12218)
Updated DBMD.supportsCorrelatedQueries() to
return true for versions > 4.1,
supportsGroupByUnrelated() to return
true and
getResultSetHoldability() to return
HOLD_CURSORS_OVER_COMMIT.
(Bug #11498)
Lifted restriction of changing streaming parameters with
server-side prepared statements. As long as
all streaming parameters were set before
execution, .clearParameters() does not have
to be called. (due to limitation of client/server protocol,
prepared statements can not reset
individual stream data on the server side).
(Bug #11498)
Bugs Fixed
Fixed connecting without a database specified raised an
exception in MysqlIO.changeDatabaseTo().
Initial implemention of ParameterMetadata for
PreparedStatement.getParameterMetadata().
Only works fully for CallableStatements, as
current server-side prepared statements return every parameter
as a VARCHAR type.
Bugs Fixed
Fixed PreparedStatement.setClob() not
accepting null as a parameter.
(Bug #11360)
Actually write manifest file to correct place so it ends up in the binary jar file. (Bug #10144)
Try to handle OutOfMemoryErrors more
gracefully. Although not much can be done, they will in most
cases close the connection they happened on so that further
operations don't run into a connection in some unknown state.
When an OOM has happened, any further operations on the
connection will fail with a “Connection closed”
exception that will also list the OOM exception as the reason
for the implicit connection close event.
(Bug #10850)
autoReconnect ping causes exception on
connection startup.
(Bug #11259)
Reorganized directory layout. Sources now are in
src folder. Don't pollute parent directory
when building, now output goes to ./build,
distribution goes to ./dist.
(Bug #10496)
Connection.setCatalog() is now aware of the
useLocalSessionState configuration property,
which when set to true will prevent the
driver from sending USE ... to the server if
the requested catalog is the same as the current catalog.
(Bug #11115)
Setting cachePrepStmts=true now causes the
Connection to also cache the check the driver
performs to determine if a prepared statement can be server-side
or not, as well as caches server-side prepared statements for
the lifetime of a connection. As before, the
prepStmtCacheSize parameter controls the size
of these caches.
(Bug #10850)
Don't send COM_RESET_STMT for each execution
of a server-side prepared statement if it isn't required.
(Bug #10850)
3-0-Compat: Compatibility with Connector/J
3.0.x functionality
(Bug #11115)
Production package doesn't include JBoss integration classes. (Bug #11411)
maxPerformance: Maximum performance without
being reckless
(Bug #11115)
Unsigned SMALLINT treated as
signed for ResultSet.getInt(), fixed all
cases for UNSIGNED integer values and
server-side prepared statements, as well as
ResultSet.getObject() for UNSIGNED
TINYINT.
(Bug #10156)
solarisMaxPerformance: Maximum performance
for Solaris, avoids syscalls where it can
(Bug #11115)
Added maintainTimeStats configuration
property (defaults to true), which tells the
driver whether or not to keep track of the last query time and
the last successful packet sent to the server's time. If set to
false, removes two syscalls per query.
(Bug #11115)
0-length streams not sent to server when using server-side prepared statements. (Bug #10850)
The data type returned for TINYINT(1) columns
when tinyInt1isBit=true (the default) can be
switched between Types.BOOLEAN and
Types.BIT using the new configuration
property transformedBitIsBoolean, which
defaults to false. If set to
false (the default),
DatabaseMetaData.getColumns() and
ResultSetMetaData.getColumnType() will return
Types.BOOLEAN for
TINYINT(1) columns. If
true, Types.BOOLEAN will
be returned instead. Regardless of this configuration property,
if tinyInt1isBit is enabled, columns with the
type TINYINT(1) will be returned as
java.lang.Boolean instances from
ResultSet.getObject(...), and
ResultSetMetaData.getColumnClassName() will
return java.lang.Boolean.
(Bug #10485)
VARBINARY data corrupted when
using server-side prepared statements and
ResultSet.getBytes().
(Bug #11115)
Added createDatabaseIfNotExist property
(default is false), which will cause the
driver to ask the server to create the database specified in the
URL if it doesn't exist. You must have the appropriate
privileges for database creation for this to work.
(Bug #10144)
SQLException thrown when retrieving
YEAR(2) with
ResultSet.getString(). The driver will now
always treat YEAR types as
java.sql.Dates and return the correct values
for getString(). Alternatively, the
yearIsDateType connection property can be set
to false and the values will be treated as
SHORTs.
(Bug #10485)
Connector/J dumping query into SQLException
twice.
(Bug #11360)
Made ServerPreparedStatement.asSql() work
correctly so auto-explain functionality would work with
server-side prepared statements.
(Bug #10155)
Double quotation marks not recognized when parsing client-side prepared statements. (Bug #10155)
Removed nonsensical “costly type conversion” warnings when using usage advisor. (Bug #11411)
com.mysql.jdbc.PreparedStatement.ParseInfo
does unnecessary call to toCharArray().
(Bug #9064)
Driver doesn't support {?=CALL(...)} for
calling stored functions. This involved adding support for
function retrieval to
DatabaseMetaData.getProcedures() and
getProcedureColumns() as well.
(Bug #10310)
Memory leak in ServerPreparedStatement if
serverPrepare() fails.
(Bug #10144)
Added support/bug hunting feature that generates
.sql test scripts to
STDERR when
autoGenerateTestcaseScript is set to
true.
(Bug #10496)
Driver detects if you're running MySQL-5.0.7 or later, and does
not scan for LIMIT ?[,?] in statements being
prepared, as the server supports those types of queries now.
(Bug #10850)
SQLException is thrown when using property
characterSetResults with
cp932 or eucjpms.
(Bug #10496)
Made JDBC2-compliant wrappers public to enable access to vendor extensions. (Bug #10155)
Added the following configuration bundles, use one or many using
the useConfigs configuration property:
maxPerformance: Maximum performance
without being reckless
solarisMaxPerformance: Maximum
performance for Solaris, avoids syscalls where it can
3-0-Compat: Compatibility with
Connector/J 3.0.x functionality
(Bug #11115)
DatabaseMetaData.supportsMultipleOpenResults()
now returns true. The driver has supported
this for some time, DBMD just missed that fact.
(Bug #10155)
Cleaned up logging of profiler events, moved code to dump a
profiler event as a string to
com.mysql.jdbc.log.LogUtils so that third
parties can use it.
(Bug #10155)
Made enableStreamingResults() visible on
com.mysql.jdbc.jdbc2.optional.StatementWrapper.
(Bug #10155)
Overhaul of character set configuration, everything now lives in a properties file.
Driver now correctly uses CP932 if available on the server for Windows-31J, CP932 and MS932 java encoding names, otherwise it resorts to SJIS, which is only a close approximation. Currently only MySQL-5.0.3 and newer (and MySQL-4.1.12 or .13, depending on when the character set gets backported) can reliably support any variant of CP932.
Bugs Fixed
Added finalizers to ResultSet and
Statement implementations to be JDBC
spec-compliant, which requires that if not explicitly closed,
these resources should be closed upon garbage collection.
(Bug #9319)
Should accept null for name patterns in DBMD
(meaning “%”), even though it
isn't JDBC compliant, for legacy's sake. Disable by setting
connection property nullNamePatternMatchesAll
to false (which will be the default value in
C/J 3.2.x).
(Bug #9769)
Check for empty strings ('') when converting
CHAR/VARCHAR
column data to numbers, throw exception if
emptyStringsConvertToZero configuration
property is set to false (for
backward-compatibility with 3.0, it is now set to
true by default, but will most likely default
to false in 3.2).
(Bug #8803)
The performance metrics feature now gathers information about number of tables referenced in a SELECT. (Bug #9704)
Fixed driver not returning true for
-1 when
ResultSet.getBoolean() was called on result
sets returned from server-side prepared statements.
(Bug #9778)
ServerPreparedStatements now correctly
“stream”
BLOB/CLOB data
to the server. You can configure the threshold chunk size using
the JDBC URL property blobSendChunkSize (the
default is 1MB).
(Bug #8868)
The logging system is now automatically configured. If the value
has been set by the user, using the URL property
logger or the system property
com.mysql.jdbc.logger, then use that,
otherwise, autodetect it using the following steps:
Log4j, if it is available,
Then JDK1.4 logging,
Then fallback to our STDERR logging.
(Bug #9704)
Added a Manifest.MF file with
implementation information to the .jar
file.
(Bug #9778)
Should accept null for catalog (meaning use
current) in DBMD methods, even though it is not JDBC-compliant
for legacy's sake. Disable by setting connection property
nullCatalogMeansCurrent to
false (which will be the default value in C/J
3.2.x).
(Bug #9917)
More tests in Field.isOpaqueBinary() to
distinguish opaque binary (that is, fields with type
CHAR(n) and CHARACTER SET
BINARY) from output of various scalar and aggregate
functions that return strings.
(Bug #9778)
DBMD.getTables() shouldn't return tables if
views are asked for, even if the database version doesn't
support views.
(Bug #9778)
Added support for the c3p0 connection pool's
(http://c3p0.sf.net/) validation/connection
checker interface which uses the lightweight
COM_PING call to the server if available. To
use it, configure your c3p0 connection pool's
connectionTesterClassName property to use
com.mysql.jdbc.integration.c3p0.MysqlConnectionTester.
(Bug #9320)
DATA_TYPE column from
DBMD.getBestRowIdentifier() causes
ArrayIndexOutOfBoundsException when accessed
(and in fact, didn't return any value).
(Bug #8803)
DATE_FORMAT() queries returned as
BLOBs from
getObject().
(Bug #8868)
A continuation of Bug #8868, where functions used in queries
that should return nonstring types when resolved by temporary
tables suddenly become opaque binary strings (work-around for
server limitation). Also fixed fields with type of
CHAR(n) CHARACTER SET BINARY to return
correct/matching classes for
RSMD.getColumnClassName() and
ResultSet.getObject().
(Bug #9236)
PreparedStatement.getMetaData() inserts blank
row in database under certain conditions when not using
server-side prepared statements.
(Bug #9320)
Better detection of LIMIT inside/outside of
quoted strings so that the driver can more correctly determine
whether a prepared statement can be prepared on the server or
not.
(Bug #9320)
Stored procedures with DECIMAL
parameters with storage specifications that contained
“,” in them would fail.
(Bug #9682)
Server-side session variables can be preset at connection time
by passing them as a comma-delimited list for the connection
property sessionVariables.
(Bug #8868)
Connection.canHandleAsPreparedStatement() now
makes “best effort” to distinguish
LIMIT clauses with placeholders in them from
ones without to have fewer false positives when generating
work-arounds for statements the server cannot currently handle
as server-side prepared statements.
(Bug #9320)
BlobFromLocator now uses correct identifier
quoting when generating prepared statements.
(Bug #8868)
Statement.getMoreResults() could throw NPE
when existing result set was .close()d.
(Bug #9704)
PreparedStatement.addBatch() doesn't work
with server-side prepared statements and streaming
BINARY data.
(Bug #9040)
Fixed build.xml to not compile
log4j logging if log4j not
available.
(Bug #9320)
Cannot use UTF-8 for characterSetResults
configuration property.
(Bug #9206)
PreparedStatement.setObject(int, Object, int type, int
scale) now uses scale value for
BigDecimal instances.
(Bug #9682)
DBMD.supportsResultSetConcurrency() not
returning true for forward-only/read-only
result sets (we obviously support this).
(Bug #8792)
Fixed regression in ping() for users using
autoReconnect=true.
(Bug #8868)
Stored procedures with same name in different databases confuse the driver when it tries to determine parameter counts/types. (Bug #9319)
DBMD.supportsMixedCase*Identifiers() returns
wrong value on servers running on case-sensitive file systems.
(Bug #8800)
Fixed DatabaseMetaData.getTables() returning
views when they were not asked for as one of the requested table
types.
Added support for new precision-math
DECIMAL type in MySQL 5.0.3 and
up.
Made Connection.ping() a public method.
Fixed ResultSet.getTime() on a
NULL value for server-side prepared
statements throws NPE.
Bugs Fixed
Infinite recursion when “falling back” to master in failover configuration. (Bug #7952)
Disable multi-statements (if enabled) for MySQL-4.1 versions prior to version 4.1.10 if the query cache is enabled, as the server returns wrong results in this configuration. (Bug #7952)
Added support for BIT type in
MySQL-5.0.3. The driver will treat BIT(1-8)
as the JDBC standard BIT type
(which maps to java.lang.Boolean), as the
server does not currently send enough information to determine
the size of a bitfield when < 9 bits are declared.
BIT(>9) will be treated as
VARBINARY, and will return
byte[] when getObject() is
called.
(Bug #8424)
Added useLocalSessionState configuration
property, when set to true the JDBC driver
trusts that the application is well-behaved and only sets
autocommit and transaction isolation levels using the methods
provided on java.sql.Connection, and
therefore can manipulate these values in many cases without
incurring round-trips to the database server.
(Bug #8424)
Fixed synchronization issue with
ServerPreparedStatement.serverPrepare() that
could cause deadlocks/crashes if connection was shared between
threads.
(Bug #8096)
Added holdResultsOpenOverStatementClose
property (default is false), that keeps
result sets open over statement.close() or new execution on same
statement (suggested by Kevin Burton).
(Bug #7715)
Removed dontUnpackBinaryResults
functionality, the driver now always stores results from
server-side prepared statements as is from the server and
unpacks them on demand.
(Bug #7952)
Detect new sql_mode variable in
string form (it used to be integer) and adjust quoting method
for strings appropriately.
(Bug #7715)
Choose correct “direction” to apply time
adjustments when both client and server are in GMT time zone
when using ResultSet.get(..., cal) and
PreparedStatement.set(...., cal).
(Bug #4718)
Fixed duplicated code in
configureClientCharset() that prevented
useOldUTF8Behavior=true from working
properly.
(Bug #7952)
Remove _binary introducer from parameters
used as in/out parameters in
CallableStatement.
(Bug #4718)
Always return byte[]s for output parameters
registered as *BINARY.
(Bug #4718)
Timestamps converted incorrectly to strings with server-side prepared statements and updatable result sets. (Bug #7715)
By default, the driver now scans SQL you are preparing using all
variants of Connection.prepareStatement() to
determine if it is a supported type of statement to prepare on
the server side, and if it is not supported by the server, it
instead prepares it as a client-side emulated prepared
statement. You can disable this by passing
emulateUnsupportedPstmts=false in your JDBC
URL.
(Bug #4718)
Emulated locators corrupt binary data when using server-side prepared statements. (Bug #8096)
Added enableStreamingResults() to
Statement for connection pool implementations
that check Statement.setFetchSize() for
specification-compliant values. Call
Statement.setFetchSize(>=0) to disable the
streaming results for that statement.
(Bug #8424)
Added dontTrackOpenResources option (default
is false, to be JDBC compliant), which helps
with memory use for nonwell-behaved apps (that is, applications
that don't close Statement objects when they
should).
(Bug #4718)
Fixed NPE in ResultSet.realClose() when using
usage advisor and result set was already closed.
(Bug #8428)
ResultSet.getBigDecimal() throws exception
when rounding would need to occur to set scale. The driver now
chooses a rounding mode of “half up” if nonrounding
BigDecimal.setScale() fails.
(Bug #8424)
Send correct value for “boolean”
true to server for
PreparedStatement.setObject(n, "true",
Types.BIT).
(Bug #4718)
Timestamp key column data needed _binary
stripped for UpdatableResultSet.refreshRow().
(Bug #7686)
PreparedStatements not creating streaming
result sets.
(Bug #8487)
ResultSet.getString() doesn't maintain format
stored on server, bug fix only enabled when
noDatetimeStringSync property is set to
true (the default is
false).
(Bug #8428)
Fixed bug with Connection not caching statements from
prepareStatement() when the statement wasn't
a server-side prepared statement.
(Bug #4718)
Don't pass NULL to
String.valueOf() in
ResultSet.getNativeConvertToString(), as it
stringifies it (that is, returns null), which
is not correct for the method in question.
(Bug #8487)
Bugs Fixed
DBMD.getProcedures() doesn't respect catalog
parameter.
(Bug #7026)
Fixed hang on SocketInputStream.read() with
Statement.setMaxRows() and multiple result
sets when driver has to truncate result set directly, rather
than tacking a LIMIT
on the end of it.
n
Bugs Fixed
Removed unwanted new Throwable() in
ResultSet constructor due to bad merge
(caused a new object instance that was never used for every
result set created). Found while profiling for Bug #6359.
(Bug #6225)
Use 1MB packet for sending file for
LOAD DATA LOCAL
INFILE if that is <
max_allowed_packet on server.
(Bug #6537)
Use our own implementation of buffered input streams to get
around blocking behavior of
java.io.BufferedInputStream. Disable this
with useReadAheadInput=false.
(Bug #6399)
Added experimental configuration property
dontUnpackBinaryResults, which delays
unpacking binary result set values until they're asked for, and
only creates object instances for nonnumeric values (it is set
to false by default). For some usecase/jvm
combinations, this is friendlier on the garbage collector.
(Bug #5706)
Fixed batched updates with server prepared statements weren't looking if the types had changed for a given batched set of parameters compared to the previous set, causing the server to return the error “Wrong arguments to mysql_stmt_execute()”. (Bug #5235)
Make auto-deserialization of
java.lang.Objects stored in
BLOB columns configurable using
autoDeserialize property (defaults to
false).
(Bug #6399)
Don't throw exceptions for
Connection.releaseSavepoint().
(Bug #5706)
ServerSidePreparedStatement allocating
short-lived objects unnecessarily.
(Bug #6225)
Inefficient detection of pre-existing string instances in
ResultSet.getNativeString().
(Bug #5706)
UNSIGNED BIGINT unpacked incorrectly from
server-side prepared statement result sets.
(Bug #5729)
Use null-safe-equals for key comparisons in updatable result sets. (Bug #6225)
Failing to connect to the server when one of the addresses for
the given host name is IPV6 (which the server does not yet bind
on). The driver now loops through all IP
addresses for a given host, and stops on the first one that
accepts() a
socket.connect().
(Bug #6348)
ResultSetMetaData.getColumnDisplaySize()
returns incorrect values for multi-byte charsets.
(Bug #6399)
SUM() on
DECIMAL with server-side prepared
statement ignores scale if zero-padding is needed (this ends up
being due to conversion to DOUBLE
by server, which when converted to a string to parse into
BigDecimal, loses all “padding”
zeros).
(Bug #6537)
Use a per-session Calendar instance by
default when decoding dates from
ServerPreparedStatements (set to old, less
performant behavior by setting property
dynamicCalendars=true).
(Bug #5706)
Handle case when string representation of timestamp contains
trailing “.” with no numbers
following it.
(Bug #5235)
Use
DatabaseMetaData.getIdentifierQuoteString()
when building DBMD queries.
(Bug #6537)
Re-work Field.isOpaqueBinary() to detect
CHAR( to support fixed-length binary fields for
n) CHARACTER SET
BINARYResultSet.getObject().
(Bug #6399)
Server-side prepared statements did not honor
zeroDateTimeBehavior property, and would
cause class-cast exceptions when using
ResultSet.getObject(), as the all-zero string
was always returned.
(Bug #5235)
Fixed too-early creation of StringBuffer in
EscapeProcessor.escapeSQL(), also return
String when escaping not needed (to avoid
unnecessary object allocations). Found while profiling for Bug
#6359.
(Bug #6225)
Fix comparisons made between string constants and dynamic
strings that are converted with either
toUpperCase() or
toLowerCase() to use
Locale.ENGLISH, as some locales
“override” case rules for English. Also use
StringUtils.indexOfIgnoreCase() instead of
.toUpperCase().indexOf(), avoids creating a
very short-lived transient String instance.
Bugs Fixed
Fixed ServerPreparedStatement to read
prepared statement metadata off the wire, even though it is
currently a placeholder instead of using
MysqlIO.clearInputStream() which didn't work
at various times because data wasn't available to read from the
server yet. This fixes sporadic errors users were having with
ServerPreparedStatements throwing
ArrayIndexOutOfBoundExceptions.
(Bug #5032)
Optimized integer number parsing, enable “old”
slower integer parsing using JDK classes using
useFastIntParsing=false property.
(Bug #4642)
Track packet sequence numbers if
enablePacketDebug=true, and throw an
exception if packets received out-of-order.
(Bug #4689)
ResultSet.wasNull() does not work for
primitives if a previous null was returned.
(Bug #4689)
Added three ways to deal with all-zero datetimes when reading
them from a ResultSet:
exception (the default), which throws an
SQLException with an SQLState of
S1009; convertToNull,
which returns NULL instead of the date; and
round, which rounds the date to the nearest
closest value which is '0001-01-01'.
(Bug #5032)
Added useOnlyServerErrorMessages property,
which causes message text in exceptions generated by the server
to only contain the text sent by the server (as opposed to the
SQLState's “standard” description, followed by the
server's error message). This property is set to
true by default.
(Bug #4642)
The driver is more strict about truncation of numerics on
ResultSet.get*(), and will throw an
SQLException when truncation is detected. You
can disable this by setting
jdbcCompliantTruncation to
false (it is enabled by default, as this
functionality is required for JDBC compliance).
(Bug #5032)
ResultSet.getObject() returns wrong type for
strings when using prepared statements.
(Bug #4482)
ServerPreparedStatements dealing with return
of DECIMAL type don't work.
(Bug #5012)
Calling MysqlPooledConnection.close() twice
(even though an application error), caused NPE. Fixed.
(Bug #4482)
Connector/J 3.1.3 beta does not handle integers correctly
(caused by changes to support unsigned reads in
Buffer.readInt() ->
Buffer.readShort()).
(Bug #4510)
You can now use URLs in
LOAD DATA LOCAL
INFILE statements, and the driver will use Java's
built-in handlers for retrieving the data and sending it to the
server. This feature is not enabled by default, you must set the
allowUrlInLocalInfile connection property to
true.
(Bug #5032)
Added support in DatabaseMetaData.getTables()
and getTableTypes() for views, which are now
available in MySQL server 5.0.x.
(Bug #4510)
ServerPreparedStatement.execute*() sometimes
threw ArrayIndexOutOfBoundsException when
unpacking field metadata.
(Bug #4642)
ResultSet.getObject() doesn't return type
Boolean for pseudo-bit types from prepared
statements on 4.1.x (shortcut for avoiding extra type conversion
when using binary-encoded result sets obscured test in
getObject() for “pseudo” bit
type).
(Bug #5032)
Use com.mysql.jdbc.Message's classloader when
loading resource bundle, should fix sporadic issues when the
caller's classloader can't locate the resource bundle.
(Bug #5032)
Bugs Fixed
Externalized more messages (on-going effort). (Bug #4119)
Support new time zone variables in MySQL-4.1.3 when
useTimezone=true.
(Bug #4311)
Null bitmask sent for server-side prepared statements was incorrect. (Bug #4119)
Added constants for MySQL error numbers (publicly accessible,
see com.mysql.jdbc.MysqlErrorNumbers), and
the ability to generate the mappings of vendor error codes to
SQLStates that the driver uses (for documentation purposes).
(Bug #4119)
Added packet debugging code (see the
enablePacketDebug property documentation).
(Bug #4119)
Error in retrieval of mediumint column with
prepared statements and binary protocol.
(Bug #4311)
Use SQL Standard SQL states by default, unless
useSqlStateCodes property is set to
false.
(Bug #4119)
Support for unsigned numerics as return types from prepared
statements. This also causes a change in
ResultSet.getObject() for the bigint
unsigned type, which used to return
BigDecimal instances, it now returns
instances of java.lang.BigInteger.
(Bug #4311)
Added support for INOUT parameters in
CallableStatements.
Mangle output parameter names for
CallableStatements so they will not clash
with user variable names.
Bugs Fixed
Fixed DatabaseMetaData.getProcedures() when
run on MySQL-5.0.0 (output of SHOW
PROCEDURE STATUS changed between 5.0.0 and 5.0.1.
(Bug #3520)
Fixed case when no output parameters specified for a stored procedure caused a bogus query to be issued to retrieve out parameters, leading to a syntax error from the server.
Correctly map output parameters to position given in
prepareCall() versus. order implied during
registerOutParameter().
(Bug #3146)
Added connectionCollation property to cause
driver to issue set collation_connection=...
query on connection init if default collation for given charset
is not appropriate.
(Bug #3520)
ServerPreparedStatements weren't actually
de-allocating server-side resources when
.close() was called.
Don't enable server-side prepared statements for server version 5.0.0 or 5.0.1, as they aren't compatible with the '4.1.2+' style that the driver uses (the driver expects information to come back that isn't there, so it hangs). (Bug #3804)
getProcedures() does not return any
procedures in result set.
(Bug #3539)
Fixed stored procedure parameter parsing info when size was
specified for a parameter (for example,
char(), varchar()).
Removed wrapping of exceptions in
MysqlIO.changeUser().
getWarnings() returns
SQLWarning instead of
DataTruncation.
(Bug #3804)
Cleaned up detection of server properties. (Bug #3146)
Correctly detect initial character set for servers >= 4.1.0. (Bug #3146)
Support placeholder for parameter metadata for server >= 4.1.2. (Bug #3146)
Added logSlowQueries property, along with
slowQueriesThresholdMillis property to
control when a query should be considered “slow.”
Added .toString() functionality to
ServerPreparedStatement, which should help if
you're trying to debug a query that is a prepared statement (it
shows SQL as the server would process).
Fixed sending of split packets for large queries, enabled nio ability to send large packets as well.
Enabled callable statement caching using
cacheCallableStmts property.
Fixed case when no parameters could cause a
NullPointerException in
CallableStatement.setOutputParameters().
Added gatherPerformanceMetrics property,
along with properties to control when/where this info gets
logged (see docs for more info).
DBMD.getSQLStateType() returns incorrect
value.
(Bug #3520)
getProcedureColumns() doesn't work with
wildcards for procedure name.
(Bug #3540)
Bugs Fixed
Fixed charset conversion issue in
getTables().
(Bug #2502)
Fixed ConnectionProperties that weren't
properly exposed through accessors, cleaned up
ConnectionProperties code.
(Bug #2623)
Prepared Statements will be re-prepared on
auto-reconnect. Any errors encountered are postponed until first
attempt to re-execute the re-prepared statement.
Reduced number of methods called in average query to be more efficient.
Refactored how connection properties are set and exposed as
DriverPropertyInfo as well as
Connection and DataSource
properties.
Fixed stack overflow in
Connection.prepareCall() (bad merge).
Enabled streaming of result sets from server-side prepared statements. (Bug #2606)
Allow contents of PreparedStatement.setBlob()
to be retained between calls to .execute*().
Fixed IllegalAccessError to
Calendar.getTimeInMillis() in
DateTimeValue (for JDK < 1.4).
Default result set type changed to
TYPE_FORWARD_ONLY (JDBC compliance).
Fixed bug with UpdatableResultSets not using
client-side prepared statements.
Class-cast exception when using scrolling result sets and server-side prepared statements. (Bug #2623)
Display where/why a connection was implicitly closed (to aid debugging). (Bug #1673)
DatabaseMetaData.getColumns() is not
returning correct column ordinal info for
non-'%' column name patterns.
(Bug #1673)
Centralized setting of result set type and concurrency.
Implemented Connection.prepareCall(), and
DatabaseMetaData.
getProcedures() and
getProcedureColumns().
(Bug #2359)
Implemented multiple result sets returned from a statement or stored procedure. (Bug #2502)
Fixed NullPointerException in
ServerPreparedStatement.setTimestamp(), as
well as year and month discrepencies in
ServerPreparedStatement.setTimestamp(),
setDate().
(Bug #1673)
Fixed character encoding issues when converting bytes to ASCII when MySQL doesn't provide the character set, and the JVM is set to a multi-byte encoding (usually affecting retrieval of numeric values).
Support “old” profileSql
capitalization in ConnectionProperties. This
property is deprecated, you should use
profileSQL if possible.
Added ability to have multiple database/JVM targets for
compliance and regression/unit tests in
build.xml.
(Bug #1673)
Support for transaction savepoints (MySQL >= 4.0.14 or 4.1.1).
Check for closed connection on delete/update/insert row
operations in UpdatableResultSet.
Support for NIO. Use useNIO=true on platforms
that support NIO.
Fixed sending of queries larger than 16M. (Bug #1673)
Use DocBook version of docs for shipped versions of drivers. (Bug #2671)
Merged fix of data type mapping from MySQL type
FLOAT to
java.sql.Types.REAL from 3.0 branch.
(Bug #1673)
Merged prepared statement caching, and
.getMetaData() support from 3.0 branch.
(Bug #2359)
Fixed NPE and year/month bad conversions when accessing some
datetime functionality in
ServerPreparedStatements and their resultant
result sets.
(Bug #1673)
Removed useFastDates connection property.
Added named and indexed input/output parameter support to
CallableStatement. MySQL-5.0.x or newer.
(Bug #1673)
Fixed off-by-1900 error in some cases for years in
TimeUtil.fastDate/TimeCreate()
when unpacking results from server-side prepared statements.
(Bug #2359)
Support for mysql_change_user().
See the changeUser() method in
com.mysql.jdbc.Connection.
DatabaseMetaData now reports
supportsStoredProcedures() for MySQL versions
>= 5.0.0
Deal with 0-length tokens in EscapeProcessor
(caused by callable statement escape syntax).
Reset long binary parameters in
ServerPreparedStatement when
clearParameters() is called, by sending
COM_RESET_STMT to the server.
(Bug #2359)
Server-side prepared statements were not returning data type
YEAR correctly.
(Bug #2606)
NULL fields were not being encoded correctly
in all cases in server-side prepared statements.
(Bug #2671)
Implemented long data (Blobs, Clobs, InputStreams, Readers) for server prepared statements.
Correctly initialize datasource properties from JNDI Refs, including explicitly specified URLs.
Ensure that warnings are cleared before executing queries on prepared statements, as-per JDBC spec (now that we support warnings).
Implemented Statement.getWarnings() for
MySQL-4.1 and newer (using SHOW
WARNINGS).
Unpack “unknown” data types from server prepared
statements as Strings.
NULL values for numeric types in binary
encoded result sets causing
NullPointerExceptions.
(Bug #2359)
CommunicationsException implemented, that
tries to determine why communications was lost with a server,
and displays possible reasons when
.getMessage() is called.
(Bug #1673)
Fixed rare buffer underflow when writing numbers into buffers for sending prepared statement execution requests. (Bug #2671)
Fix support for table aliases when checking for all primary keys
in UpdatableResultSet.
Optimized Buffer.readLenByteArray() to return
shared empty byte array when length is 0.
Detect collation of column for
RSMD.isCaseSensitive().
(Bug #1673)
Merged unbuffered input code from 3.0. (Bug #2623)
Bugs Fixed
Track open Statements, close all when
Connection.close() is called (JDBC
compliance).
Added requireSSL property.
Added useServerPrepStmts property (default
false). The driver will use server-side
prepared statements when the server version supports them (4.1
and newer) when this property is set to true.
It is currently set to false by default until
all bind/fetch functionality has been implemented. Currently
only DML prepared statements are implemented for 4.1 server-side
prepared statements.
Bugs Fixed
PreparedStatement.fixDecimalExponent() adding
extra +, making number unparseable by MySQL
server.
(Bug #7061)
Workaround for server Bug #9098: Default values of
CURRENT_* for
DATE,
TIME,
DATETIME, and
TIMESTAMP columns can't be
distinguished from string values, so
UpdatableResultSet.moveToInsertRow()
generates bad SQL for inserting default values.
(Bug #8812)
Handle streaming result sets with more than 2 billion rows properly by fixing wraparound of row number counter. (Bug #7601)
Fixed duplicated code in
configureClientCharset() that prevented
useOldUTF8Behavior=true from working
properly.
(Bug #7952)
Statements created from a pooled connection were returning
physical connection instead of logical connection when
getConnection() was called.
(Bug #7316)
MS932, SHIFT_JIS, and
Windows_31J not recognized as aliases for
sjis.
(Bug #7607)
EUCKR charset is sent as SET NAMES
euc_kr which MySQL-4.1 and newer doesn't understand.
(Bug #8629)
Support new protocol type MYSQL_TYPE_VARCHAR.
(Bug #7081)
Connections starting up failed-over (due to down master) never retry master. (Bug #6966)
PreparedStatements don't encode Big5 (and
other multi-byte) character sets correctly in static SQL
strings.
(Bug #7033)
PreparedStatement.fixDecimalExponent() adding
extra +, making number unparseable by MySQL
server.
(Bug #7601)
Backported SQLState codes mapping from Connector/J 3.1, enable
with useSqlStateCodes=true as a connection
property, it defaults to false in this
release, so that we don't break legacy applications (it defaults
to true starting with Connector/J 3.1).
(Bug #7686)
Added useOldUTF8Behavior' configuration
property, which causes JDBC driver to act like it did with
MySQL-4.0.x and earlier when the character encoding is
utf-8 when connected to MySQL-4.1 or newer.
(Bug #7081)
Escape sequence {fn convert(..., type)} now supports ODBC-style
types that are prepended by SQL_.
(Bug #7601)
Added support for the EUC_JP_Solaris
character encoding, which maps to a MySQL encoding of
eucjpms (backported from 3.1 branch). This
only works on servers that support eucjpms,
namely 5.0.3 or later.
(Bug #8629)
NON_UNIQUE column from
DBMD.getIndexInfo() returned inverted value.
(Bug #8812)
Use hex escapes for
PreparedStatement.setBytes() for double-byte
charsets including “aliases”
Windows-31J, CP934,
MS932.
(Bug #8629)
Timestamp key column data needed _binary
stripped for UpdatableResultSet.refreshRow().
(Bug #7686)
DatabaseMetaData.getIndexInfo() ignored
unique parameter.
(Bug #7081)
DatabaseMetaData.supportsSelectForUpdate()
returns correct value based on server version.
(Bug #8629)
Which requires hex escaping of binary data when using multi-byte charsets with prepared statements. (Bug #8064)
Timestamp/Time conversion
goes in the wrong “direction” when
useTimeZone=true and server time zone differs
from client time zone.
(Bug #5874)
Adding CP943 to aliases for
sjis.
(Bug #6549, Bug #7607)
Bugs Fixed
Made TINYINT(1) ->
BIT/Boolean
conversion configurable using tinyInt1isBit
property (default true to be JDBC compliant
out of the box).
(Bug #5664)
Off-by-one bug in
Buffer.readString(.
(Bug #5664)string)
ResultSet.updateByte() when on insert row
throws ArrayOutOfBoundsException.
(Bug #5664)
Fixed regression where useUnbufferedInput was
defaulting to false.
(Bug #5664)
ResultSet.getTimestamp() on a column with
TIME in it fails.
(Bug #5664)
Fixed DatabaseMetaData.getTypes() returning
incorrect (this is, nonnegative) scale for the
NUMERIC type.
(Bug #5664)
Only set character_set_results
during connection establishment if server version >= 4.1.1.
(Bug #5664)
Re-issue character set configuration commands when re-using
pooled connections or Connection.changeUser()
when connected to MySQL-4.1 or newer.
Fixed ResultSetMetaData.isReadOnly() to
detect nonwritable columns when connected to MySQL-4.1 or newer,
based on existence of “original” table and column
names.
Bugs Fixed
Calling .close() twice on a
PooledConnection causes NPE.
(Bug #4808)
“Production” is now “GA” (General Availability) in naming scheme of distributions. (Bug #4860, Bug #4138)
DOUBLE mapped twice in
DBMD.getTypeInfo().
(Bug #4742)
Removed redundant calls to checkRowPos() in
ResultSet.
(Bug #4334)
DBMD.getColumns() returns incorrect JDBC type
for unsigned columns. This affects type mappings for all numeric
types in the RSMD.getColumnType() and
RSMD.getColumnTypeNames() methods as well, to
ensure that “like” types from
DBMD.getColumns() match up with what
RSMD.getColumnType() and
getColumnTypeNames() return.
(Bug #4860, Bug #4138)
ResultSet.getMetaData() should not return
incorrectly initialized metadata if the result set has been
closed, but should instead throw an
SQLException. Also fixed for
getRow() and getWarnings()
and traversal methods by calling
checkClosed() before operating on
instance-level fields that are nullified during
.close().
(Bug #5069)
RSMD.getPrecision() returning 0 for
nonnumeric types (should return max length in chars for
nonbinary types, max length in bytes for binary types). This fix
also fixes mapping of RSMD.getColumnType()
and RSMD.getColumnTypeName() for the
BLOB types based on the length
sent from the server (the server doesn't distinguish between
TINYBLOB,
BLOB,
MEDIUMBLOB or
LONGBLOB at the network protocol
level).
(Bug #4880)
Added FLOSS license exemption. (Bug #4742)
ResultSet should release
Field[] instance in
.close().
(Bug #5022)
Failover for autoReconnect not using port
numbers for any hosts, and not retrying all hosts.
This required a change to the SocketFactory
connect() method signature, which is now
public Socket connect(String host, int portNumber,
Properties props); therefore, any third-party socket
factories will have to be changed to support this signature.
(Bug #4334)
Use _binary introducer for
PreparedStatement.setBytes() and
set*Stream() when connected to MySQL-4.1.x or
newer to avoid misinterpretation during character conversion.
(Bug #5069)
Logical connections created by
MysqlConnectionPoolDataSource will now issue
a rollback() when they are closed and sent
back to the pool. If your application server/connection pool
already does this for you, you can set the
rollbackOnPooledClose property to
false to avoid the overhead of an extra
rollback().
(Bug #4334)
Parse new time zone variables from 4.1.x servers. (Bug #5069)
StringUtils.escapeEasternUnicodeByteStream
was still broken for GBK.
(Bug #4010)
Bugs Fixed
Using a MySQLDatasource without server name
fails.
(Bug #3848)
PreparedStatement.getGeneratedKeys() method
returns only 1 result for batched insertions.
(Bug #3873)
No Database Selected when using
MysqlConnectionPoolDataSource.
(Bug #3920)
Bugs Fixed
Backported “change user” and “reset server
state” functionality from 3.1 branch, to enable clients
of MysqlConnectionPoolDataSource to reset
server state on getConnection() on a pooled
connection.
Made StringRegressionTest 4.1-unicode aware.
(Bug #3520)
Use SET character_set_results during
initialization to enable any charset to be returned to the
driver for result sets.
(Bug #2670)
Fixed regression in
PreparedStatement.setString() and eastern
character encodings.
(Bug #3520)
Don't truncate BLOB or
CLOB values when using
setBytes() and
setBinary/CharacterStream().
(Bug #2670)
Map duplicate key and foreign key errors to SQLState of
23000.
Allow java.util.Date to be sent in as
parameter to PreparedStatement.setObject(),
converting it to a Timestamp to maintain full
precision. .
(Bug #103)
Add unsigned attribute to
DatabaseMetaData.getColumns() output in the
TYPE_NAME column.
Not specifying database in URL caused
MalformedURL exception.
(Bug #3554)
Added failOverReadOnly property, to enable
the user to configure the state of the connection
(read-only/writable) when failed over.
Dynamically configure character set mappings for field-level
character sets on MySQL-4.1.0 and newer using
SHOW COLLATION when connecting.
(Bug #2670)
Map binary character set to
US-ASCII to support
DATETIME charset recognition for
servers >= 4.1.2.
(Bug #2670)
Inconsistent reporting of data type. The server still doesn't return all types for *BLOBs *TEXT correctly, so the driver won't return those correctly. (Bug #3570)
Auto-convert MySQL encoding names to Java encoding names if used
for characterEncoding property.
(Bug #3554)
Backport documentation tooling from 3.1 branch.
Use junit.textui.TestRunner for all unit
tests (to enable them to be run from the command line outside of
Ant or Eclipse).
(Bug #3554)
Renamed StringUtils.escapeSJISByteStream() to
more appropriate
escapeEasternUnicodeByteStream().
(Bug #3511)
Use charsetnr returned during connect to
encode queries before issuing SET NAMES on
MySQL >= 4.1.0.
(Bug #2670)
StringUtils.escapeSJISByteStream() not
covering all eastern double-byte charsets correctly.
(Bug #3511)
DBMD.getSQLStateType() returns incorrect
value.
(Bug #3520)
Add helper methods to ResultSetMetaData
(getColumnCharacterEncoding() and
getColumnCharacterSet()) to permit end users
to see what charset the driver thinks it should be using for the
column.
(Bug #2670)
Don't escape SJIS/GBK/BIG5 when using MySQL-4.1 or newer.
Added encoding names that are recognized on some JVMs to fix case where they were reverse-mapped to MySQL encoding names incorrectly. (Bug #3554)
Only set character_set_results
for MySQL >= 4.1.0.
(Bug #2670)
Return creating statement for ResultSets
created by getGeneratedKeys().
(Bug #2957)
UpdatableResultSet not picking up default
values for moveToInsertRow().
(Bug #3557)
Allow url parameter for
MysqlDataSource and
MysqlConnectionPool
DataSource so that passing of other
properties is possible from inside appservers.
Bugs Fixed
Return java.lang.Integer for
TINYINT and
SMALLINT types from
ResultSetMetaData.getColumnClassName().
(Bug #2852)
Return java.lang.Double for
FLOAT type from
ResultSetMetaData.getColumnClassName().
(Bug #2855)
Added useUnbufferedInput parameter, and now
use it by default (due to JVM issue
http://developer.java.sun.com/developer/bugParade/bugs/4401235.html)
(Bug #2578)
AutoReconnect time was growing faster than
exponentially.
(Bug #2447)
Fixed failover always going to last host in list. (Bug #2578)
Detect on/off or
1, 2, 3
form of lower_case_table_names
value on server.
(Bug #2578)
Return [B instead of
java.lang.Object for
BINARY,
VARBINARY and
LONGVARBINARY types from
ResultSetMetaData.getColumnClassName() (JDBC
compliance).
(Bug #2855)
Issue connection events on all instances created from a
ConnectionPoolDataSource.
(Bug #2855)
Trigger a SET NAMES utf8 when encoding is
forced to utf8 or
utf-8 using the
characterEncoding property. Previously, only
the Java-style encoding name of utf-8 would
trigger this.
Bugs Fixed
Fixed regression of
Statement.getGeneratedKeys() and
REPLACE statements.
(Bug #1576)
Implement ResultSet.updateClob().
(Bug #1913)
Enable caching of the parsing stage of prepared statements using
the cachePrepStmts,
prepStmtCacheSize, and
prepStmtCacheSqlLimit properties (disabled by
default).
(Bug #2006)
Foreign Keys column sequence is not consistent in
DatabaseMetaData.getImported/Exported/CrossReference().
(Bug #1731)
Subsequent call to ResultSet.updateFoo()
causes NPE if result set is not updatable.
(Bug #1630)
Backported fix for aliased tables and
UpdatableResultSets in
checkUpdatability() method from 3.1 branch.
(Bug #1534)
Fixed security exception when used in Applets (applets can't
read the system property file.encoding which
is needed for LOAD
DATA LOCAL INFILE).
(Bug #2006)
Speed up parsing of PreparedStatements, try
to use one-pass whenever possible.
(Bug #2006)
Support escape sequence {fn convert ... }. (Bug #1914)
Autoreconnect code didn't set catalog upon reconnect if it had been changed. (Bug #1913)
Fixed exception Unknown character set
'danish' on connect with JDK-1.4.0
(Bug #2006)
Fixed mappings in SQLError to report deadlocks with SQLStates of
41000.
(Bug #2006)
ResultSet.getObject() on
TINYINT and
SMALLINT columns should return
Java type Integer.
(Bug #1913)
ArrayIndexOutOfBounds when parameter number
== number of parameters + 1.
(Bug #1958)
Added more descriptive error message Server
Configuration Denies Access to DataSource, as well as
retrieval of message from server.
(Bug #1913)
“Friendlier” exception message for
PacketTooLargeException.
(Bug #1534)
Don't count quoted IDs when inside a 'string' in
PreparedStatement parsing.
(Bug #1511)
Removed static synchronization bottleneck from instance factory
method of SingleByteCharsetConverter.
(Bug #2006)
Removed static synchronization bottleneck from
PreparedStatement.setTimestamp().
(Bug #2006)
ResultSet.findColumn() should use first
matching column name when there are duplicate column names in
SELECT query (JDBC-compliance).
(Bug #2006)
maxRows property would affect internal
statements, so check it for all statement creation internal to
the driver, and set to 0 when it is not.
(Bug #2006)
Barge blobs and split packets not being read correctly. (Bug #1576)
ResultSetMetaData.isCaseSensitive() returned
wrong value for
CHAR/VARCHAR
columns.
(Bug #1913)
DatabaseMetaData.getSystemFunction()
returning bad function VResultsSion.
(Bug #1775)
Use constants for SQLStates. (Bug #2006)
Fix for 4.1.1-style authentication with no password. (Bug #1630)
Cross-database updatable result sets are not checked for updatability correctly. (Bug #1592)
Statements being created too many times in
DBMD.extractForeignKeyFromCreateTable().
(Bug #1925)
Map charset ko18_ru to
ko18r when connected to MySQL-4.1.0 or newer.
(Bug #2006)
Fix for ArrayIndexOutOfBounds exception when
using Statement.setMaxRows().
(Bug #1695)
Connection property maxRows not honored.
(Bug #1933)
Added alwaysClearStream connection property,
which causes the driver to always empty any remaining data on
the input stream before each query.
(Bug #1913)
DatabaseMetaData.getColumns() should return
Types.LONGVARCHAR for MySQL
LONGTEXT type.
(Bug #1592)
Ensure that Buffer.writeString() saves room
for the \0.
(Bug #2006)
Bugs Fixed
Issue exception on
ResultSet.get
on empty result set (wasn't caught in some cases).
(Bug #848)XXX()
Made databaseName,
portNumber, and serverName
optional parameters for
MysqlDataSourceFactory.
(Bug #1246)
ResultSet.get/setString mashing char 127.
(Bug #1247)
Double-escaping of '\' when charset is SJIS
or GBK and '\' appears in nonescaped input.
(Bug #879)
Don't hide messages from exceptions thrown in I/O layers. (Bug #848)
Support InnoDB constraint names when
extracting foreign key information in
DatabaseMetaData (implementing ideas from
Parwinder Sekhon).
(Bug #664, Bug #517)
Fixed CLOB.truncate().
(Bug #1130)
Fixed ResultSet.previous() behavior to move
current position to before result set when on first row of
result set.
(Bug #496)
Backported 4.1 protocol changes from 3.1 branch (server-side SQL states, new field information, larger client capability flags, connect-with-database, and so forth). (Bug #664, Bug #517)
Fixed Statement and
PreparedStatement issuing bogus queries when
setMaxRows() had been used and a
LIMIT clause was present in the query.
(Bug #496)
Added property to “clobber” streaming results, by
setting the clobberStreamingResults property
to true (the default is
false). This will cause a
“streaming” ResultSet to be
automatically closed, and any outstanding data still streaming
from the server to be discarded if another query is executed
before all the data has been read from the server.
(Bug #1247)
When emptying input stream of unused rows for
“streaming” result sets, have the current thread
yield() every 100 rows to not monopolize CPU
time.
(Bug #879)
Fixed deadlock issue with
Statement.setMaxRows().
(Bug #1099)
Don't wrap SQLExceptions in
RowDataDynamic.
(Bug #688)
Added com.mysql.jdbc.util.BaseBugReport to
help creation of testcases for bug reports.
(Bug #1247)
Clip +/- INF (to smallest and largest representative values for
the type in MySQL) and NaN (to 0) for
setDouble/setFloat(), and
issue a warning on the statement when the server does not
support +/- INF or NaN.
(Bug #884)
Don't try and reset isolation level on reconnect if MySQL doesn't support them. (Bug #688)
DatabaseMetaData.getColumns() getting
confused about the keyword “set” in character
columns.
(Bug #1099)
Fixed regression in large split-packet handling. (Bug #848)
Fixed test for end of buffer in
Buffer.readString().
The insertRow in an
UpdatableResultSet is now loaded with the
default column values when moveToInsertRow()
is called.
(Bug #688)
Better diagnostic error messages in exceptions for “streaming” result sets. (Bug #848)
Backported authentication changes for 4.1.1 and newer from 3.1 branch. (Bug #1247)
DatabaseMetaData.getColumns() wasn't
returning NULL for default values that are
specified as NULL.
(Bug #688)
Don't change timestamp TZ twice if
useTimezone==true.
(Bug #774)
refreshRow didn't work when primary key
values contained values that needed to be escaped (they ended up
being doubly escaped).
(Bug #661)
Fix UpdatableResultSet to return values for
get when on
insert row.
(Bug #675)XXX()
Don't fire connection closed events when closing pooled
connections, or on
PooledConnection.getConnection() with already
open connections.
(Bug #884)
Change default statement type/concurrency to
TYPE_FORWARD_ONLY and
CONCUR_READ_ONLY (spec compliance).
(Bug #688)
Faster date handling code in ResultSet and
PreparedStatement (no longer uses
Date methods that synchronize on static
calendars).
Optimized CLOB.setChracterStream().
(Bug #1131)
Bugs Fixed
Fixed SJIS encoding bug, thanks to Naoto Sato. (Bug #378)
Allow bogus URLs in Driver.getPropertyInfo().
Fix problem detecting server character set in some cases. (Bug #378)
Allow multiple calls to Statement.close().
(Bug #378)
Return correct number of generated keys when using
REPLACE statements.
(Bug #378)
Unicode character 0xFFFF in a string would cause the driver to
throw an ArrayOutOfBoundsException. .
(Bug #378)
Return list of generated keys when using multi-value
INSERTS with
Statement.getGeneratedKeys().
Fixed result set not getting set for
Statement.executeUpdate(), which affected
getGeneratedKeys() and
getUpdateCount() in some cases.
Changed Ant target compile-core to
compile-driver, and made testsuite
compilation a separate target.
Fix infinite loop with Connection.cleanup().
Fix row data decoding error when using very large packets. (Bug #378)
Optimized row data decoding. (Bug #378)
Use JVM charset with file names and LOAD DATA [LOCAL]
INFILE.
Issue exception when operating on an already closed prepared statement. (Bug #378)
Optimized usage of EscapeProcessor.
(Bug #378)
Bugs Fixed
Throw SQLExceptions when trying to do
operations on a forcefully closed Connection
(that is, when a communication link failure occurs).
Fixed ResultSet.getTimestamp() when
underlying field is of type DATE.
Fixed escaping of 0x5c ('\') character for
GBK and Big5 charsets.
Don't reset Connection.isReadOnly() when
autoReconnecting.
Ensure that packet size from
alignPacketSize() does not exceed
max_allowed_packet (JVM bug)
Don't pick up indexes that start with pri as
primary keys for DBMD.getPrimaryKeys().
Fixed LOAD DATA LOCAL
INFILE bug when file >
max_allowed_packet.
Updatable ResultSets can now be created for
aliased tables/columns when connected to MySQL-4.1 or newer.
Fixed missing conversion for YEAR
type in
ResultSetMetaData.getColumnTypeName().
Remove synchronization from Driver.connect()
and Driver.acceptsUrl().
IOExceptions during a transaction now cause
the Connection to be closed.
Fixed StringIndexOutOfBoundsException in
PreparedStatement.setClob().
Fixed MysqlPooledConnection.close() calling
wrong event type.
4.1 Column Metadata fixes.
You can now toggle profiling on/off using
Connection.setProfileSql(boolean).
Fixed charset issues with database metadata (charset was not getting set correctly).
Bugs Fixed
Add “window” of different NULL
sorting behavior to
DBMD.nullsAreSortedAtStart (4.0.2 to 4.0.10,
true; otherwise, no).
Implemented Blob.setBytes(). You still need
to pass the resultant Blob back into an
updatable ResultSet or
PreparedStatement to persist the changes,
because MySQL does not support “locators”.
More checks added in ResultSet traversal
method to catch when in closed state.
Fixed ResultSetMetaData.isWritable() to
return correct value.
Clean up Statement query/method mismatch
tests (that is, INSERT not
permitted with .executeQuery()).
Allow ignoring of warning for “non transactional
tables” during rollback (compliance/usability) by setting
ignoreNonTxTables property to
true.
Fixed ResultSetMetaData to return
"" when catalog not known. Fixes
NullPointerExceptions with Sun's
CachedRowSet.
Fixed SQLExceptions getting swallowed on
initial connect.
Fixed DBMD.getTypeInfo() and
DBMD.getColumns() returning different value
for precision in TEXT and
BLOB types.
Fixed Statement.setMaxRows() to stop sending
LIMIT type queries when not needed
(performance).
Backported 4.1 charset field info changes from Connector/J 3.1.
Bugs Fixed
Greatly reduce memory required for
setBinaryStream() in
PreparedStatements.
Retrieve TX_ISOLATION from database for
Connection.getTransactionIsolation() when the
MySQL version supports it, instead of an instance variable.
Quote table names in
DatabaseMetaData.getColumns(),
getPrimaryKeys(),
getIndexInfo(),
getBestRowIdentifier().
Fixed Buffer.fastSkipLenString() causing
ArrayIndexOutOfBounds exceptions with some
queries when unpacking fields.
Added update options for foreign key metadata.
Implemented an empty TypeMap for
Connection.getTypeMap() so that some
third-party apps work with MySQL (IBM WebSphere 5.0 Connection
pool).
Added missing
LONGTEXT type to
DBMD.getColumns().
Fixed ResultSet.isBeforeFirst() for empty
result sets.
Bugs Fixed
Added support for quoted identifiers in
PreparedStatement parser.
Added strictUpdates property to enable
control of amount of checking for “correctness” of
updatable result sets. Set this to false if
you want faster updatable result sets and you know that you
create them from SELECT
statements on tables with primary keys and that you have
selected all primary keys in your query.
Reduce memory footprint of PreparedStatements
by sharing outbound packet with MysqlIO.
Added support for 4.0.8-style large packets.
Added quoted identifiers to database names for
Connection.setCatalog.
Fixed PreparedStatement.executeBatch()
parameter overwriting.
Streamlined character conversion and byte[]
handling in PreparedStatements for
setByte().
Bugs Fixed
Changed SingleByteCharConverter to use lazy
initialization of each converter.
Fixed ResultSetMetaData.getPrecision()
returning incorrect values for some floating-point types.
Check for connection closed in more
Connection methods
(createStatement,
prepareStatement,
setTransactionIsolation,
setAutoCommit).
Some MySQL-4.1 protocol support (extended field info from selects).
More robust implementation of updatable result sets. Checks that all primary keys of the table have been selected.
DBMD.getImported/ExportedKeys() now handles
multiple foreign keys per table.
Honor lower_case_table_names
when enabled in the server when doing table name comparisons in
DatabaseMetaData methods.
Added CLIENT_LONG_FLAG to be able to get more
column flags (isAutoIncrement() being the
most important).
Substitute '?' for unknown character
conversions in single-byte character sets instead of
'\0'.
Because of above, implemented
ResultSetMetaData.isAutoIncrement() to use
Field.isAutoIncrement().
Fixed charset handling in Fields.java.
Fixed ResultSetMetaData.getColumnTypeName()
returning BLOB for
TEXT and
TEXT for
BLOB types.
Implemented Connection.nativeSQL().
LOAD DATA LOCAL INFILE ... now works, if your
server is configured to permit it. Can be turned off with the
allowLoadLocalInfile property (see the
README).
Use nonaliased table/column names and database names to fully
qualify tables and columns in
UpdatableResultSet (requires MySQL-4.1 or
newer).
Changed charsToByte in
SingleByteCharConverter to be nonstatic.
NamedPipeSocketFactory now works (only
intended for Windows), see README for
instructions.
Fixed Buffer.isLastDataPacket() for 4.1 and
newer servers.
More robust escape tokenizer: Recognize --
comments, and permit nested escape sequences (see
testsuite.EscapeProcessingTest).
Allow user to alter behavior of Statement/
PreparedStatement.executeBatch() using
continueBatchOnError property (defaults to
true).
Bugs Fixed
Implemented Clob.truncate().
Properly restore connection properties when autoReconnecting or
failing-over, including autoCommit state, and
isolation level.
Fixed issue when calling
Statement.setFetchSize() when using arbitrary
values.
Added queriesBeforeRetryMaster property that
specifies how many queries to issue when failed over before
attempting to reconnect to the master (defaults to 50).
Fixed
ResultSet.setFetchDirection(FETCH_UNKNOWN).
Added driver property useHostsInPrivileges.
Defaults to true. Affects whether or not
@hostname will be used in
DBMD.getColumn/TablePrivileges.
Fixed ResultSet.isLast() for empty result
sets (should return false).
Fixed various non-ASCII character encoding issues.
Added connectTimeout parameter that enables
users of JDK-1.4 and newer to specify a maximum time to wait to
establish a connection.
Fixed start position off-by-1 error in
Clob.getSubString().
Fixed issue with updatable result sets and
PreparedStatements not working.
PreparedStatement now honors stream lengths
in setBinary/Ascii/Character Stream() unless you set the
connection property
useStreamLengthsInPrepStmts to
false.
Escape 0x5c character in strings for the SJIS
charset.
Removed some not-needed temporary object creation by smarter use
of Strings in
EscapeProcessor,
Connection and
DatabaseMetaData classes.
Implemented ResultSet.updateBlob().
Fixed incorrect conversion in
ResultSet.getLong().
Fixed UnsupportedEncodingException thrown
when “forcing” a character encoding using
properties.
Removed duplicate code from
UpdatableResultSet (it can be inherited from
ResultSet, the extra code for each method to
handle updatability I thought might someday be necessary has not
been needed).
Implemented Clob.setAsciiStream().
Fixed DBMD.supportsResultSetConcurrency() so
that it returns true for
ResultSet.TYPE_SCROLL_INSENSITIVE and
ResultSet.CONCUR_READ_ONLY or
ResultSet.CONCUR_UPDATABLE.
Failover and autoReconnect work only when the
connection is in an autoCommit(false) state,
to stay transaction-safe.
Implemented Clob.setCharacterStream().
Use SHOW CREATE TABLE when
possible for determining foreign key information for
DatabaseMetaData. Also enables cascade
options for DELETE information to
be returned.
All DBMD result set columns describing
schemas now return NULL to be more compliant
with the behavior of other JDBC drivers for other database
systems (MySQL does not support schemas).
Added SSL support. See README for
information on how to use it.
Added com.mysql.jdbc.MiniAdmin class, which
enables you to send shutdown command to MySQL
server. This is intended to be used when
“embedding” Java and MySQL server together in an
end-user application.
Implemented Clob.setString().
Bugs Fixed
Added paranoid parameter, which sanitizes
error messages by removing “sensitive” information
from them (such as host names, ports, or user names), as well as
clearing “sensitive” data structures when possible.
Added LOCAL TEMPORARY to table types in
DatabaseMetaData.getTableTypes().
Added socketTimeout parameter to URL.
Connection.close() issues
rollback() when
getAutoCommit() is false.
Connection.isClosed() no longer
“pings” the server.
Added limited Clob functionality
(ResultSet.getClob(),
PreparedStatement.setClob(),
PreparedStatement.setObject(Clob).
Implemented ResultSet.getCharacterStream().
Massive code clean-up to follow Java coding conventions (the time had come).
Fixed ResultSet.getRow() off-by-one bug.
Fixed RowDataStatic.getAt() off-by-one bug.
Charsets now automatically detected. Optimized code for single-byte character set conversion.
Bugs Fixed
Performance enhancements: Driver is now 50–100% faster in most situations, and creates fewer temporary objects.
!!! LICENSE CHANGE !!! The
driver is now GPL. If you need non-GPL licenses, please contact
me <mark@mysql.com>.
Overall speed improvements using controlling transient object
creation in MysqlIO class when reading
packets.
JDBC-3.0 functionality including
Statement/PreparedStatement.getGeneratedKeys()
and ResultSet.getURL().
Performance improvements in string handling and field metadata creation (lazily instantiated) contributed by Alex Twisleton-Wykeham-Fiennes.
Better checking for closed connections in
Statement and
PreparedStatement.
Support for large packets (new addition to MySQL-4.0 protocol),
see README for more information.
Repackaging: New driver name is
com.mysql.jdbc.Driver, old name still works,
though (the driver is now provided by MySQL-AB).
Added multi-host failover support (see
README).
ResultSet.getDate/Time/Timestamp now
recognizes all forms of invalid values that have been set to all
zeros by MySQL (SF bug 586058).
JDBC Compliance: Passes all tests besides stored procedure tests.
Testsuite now uses Junit (which you can get from http://www.junit.org.
Support for streaming (row-by-row) result sets (see
README) Thanks to Doron.
Float types now reported as
java.sql.Types.FLOAT (SF bug 579573).
ResultSet.getTimestamp() now works for
DATE types (SF bug 559134).
Fix and sort primary key names in DBMetaData
(SF bugs 582086 and 582086).
The driver now only works with JDK-1.2 or newer.
General source-code cleanup.
Bugs Fixed
Quoted identifiers not used if server version does not support
them. Also, if server started with
--ansi or
--sql-mode=ANSI_QUOTES,
“"” will be used as an
identifier quote character, otherwise
“'” will be used.
More code cleanup.
PreparedStatement now releases resources on
.close(). (SF bug 553268)
Added SQL profiling (to STDERR). Set
profileSql=true in your JDBC URL. See
README for more information.
LogicalHandle.isClosed() calls through to
physical connection.
Fixed typo for relaxAutoCommit parameter.
ResultSet.getDouble() now uses code built
into JDK to be more precise (but slower).
Bugs Fixed
ResultSetMetaData.getColumnClassName() now
implemented.
DBMetaData.getIndexInfo() - bad PAGES fixed.
(SF BUG 542201)
Rudimentary version of
Statement.getGeneratedKeys() from JDBC-3.0
now implemented (you need to be using JDK-1.4 for this to work,
I believe).
More code cleanup.
PreparedStatement.toString() fixed. (SF bug
534026)
Added set/getPortNumber()
to DataSource(s). (SF bug 548167)
Added setURL() to
MySQLXADataSource. (SF bug 546019)
Faster blob escaping for PrepStmt.
Fixed unicode chars being read incorrectly. (SF bug 541088)
Bugs Fixed
General code cleanup.
Fixed getRow() bug (527165) in
ResultSet.
ResultSet.refreshRow() implemented.
Added getIdleFor() method to
Connection and
MysqlLogicalHandle.
Added getTable/ColumnPrivileges() to DBMD
(fixes 484502).
ResultSet: Fixed updatability (values being
set to null if not updated).
Fixes for ResultSet updatability in
PreparedStatement.
Added support for YEAR type
(533556).
DataSources - fixed setUrl
bug (511614, 525565), wrong datasource class name (532816,
528767).
Relaxed synchronization in all classes, should fix 520615 and 520393.
ResultSet.insertRow() should now detect
auto_increment fields in most cases and use that value in the
new row. This detection will not work in multi-valued keys,
however, due to the fact that the MySQL protocol does not return
this information.
Added support for BIT types
(51870) to PreparedStatement.
Added identifier quoting to all
DatabaseMetaData methods that need them
(should fix 518108).
Fixed time zone off-by-1-hour bug in
PreparedStatement (538286, 528785).
Added new types to getTypeInfo(), fixed
existing types thanks to Al Davis and Kid Kalanon.
Fixed testsuite.Traversal
afterLast() bug, thanks to Igor Lastric.
Bugs Fixed
More changes to fix Unexpected end of input
stream errors when reading
BLOB values. This should be the
last fix.
Fixed missing DELETE_RULE value in
DBMD.getImported/ExportedKeys() and
getCrossReference().
Full synchronization of Statement.java.
Bugs Fixed
Fixed spurious Unexpected end of input stream
errors in MysqlIO (bug 507456).
Fixed null-pointer-exceptions when using
MysqlConnectionPoolDataSource with Websphere
4 (bug 505839).
Bugs Fixed
Full synchronization on methods modifying instance and class-shared references, driver should be entirely thread-safe now (please let me know if you have problems).
Fixed off-by-one-hour error in
PreparedStatement.setTimestamp() (bug
491577).
Implementation of
DatabaseMetaData.getExported/ImportedKeys()
and getCrossReference().
Report batch update support through
DatabaseMetaData (bug 495101).
Ant build was corrupting included
jar files, fixed (bug 487669).
Removed concatenation support from driver (the
|| operator), as older versions of VisualAge
seem to be the only thing that use it, and it conflicts with the
logical || operator. You will need to start
mysqld with the
--ansi flag to use the
|| operator as concatenation (bug 491680).
Fixed quoting error with escape processor (bug 486265).
DataSource implementations moved to
org.gjt.mm.mysql.jdbc2.optional package, and
(initial) implementations of
PooledConnectionDataSource and
XADataSource are in place (thanks to Todd
Wolff for the implementation and testing of
PooledConnectionDataSource with IBM WebSphere
4).
Fixed casting bug in PreparedStatement (bug
488663).
Added detection of network connection being closed when reading packets (thanks to Todd Lizambri).
Fixed extra memory allocation in
MysqlIO.readPacket() (bug 488663).
Bugs Fixed
PreparedStatement.setAnyNumericType() now
handles positive exponents correctly (adds +
so MySQL can understand it).
Batch updates now supported (thanks to some inspiration from Daniel Rall).
DatabaseMetaData.getPrimaryKeys() and
getBestRowIdentifier() are now more robust in
identifying primary keys (matches regardless of case or
abbreviation/full spelling of Primary Key in
Key_type column).
XADataSource/ConnectionPoolDataSource
code (experimental)
Bugs Fixed
Fixed ResultSet.isAfterLast() always
returning false.
PreparedStatement.setBoolean() will use 1/0 for values if your MySQL version is 3.21.23 or higher.
Updatable result sets now correctly handle
NULL values in fields.
Fixed
DatabaseMetaData.supportsTransactions(), and
supportsTransactionIsolationLevel() and
getTypeInfo()
SQL_DATETIME_SUB and
SQL_DATA_TYPE fields not being readable.
PreparedStatement.setDouble() now uses full-precision doubles (reverting a fix made earlier to truncate them).
Fixed time zone issue in
PreparedStatement.setTimestamp(). (thanks to
Erik Olofsson)
Fixed dangling socket problem when in high availability
(autoReconnect=true) mode, and finalizer for
Connection will close any dangling sockets on
GC.
Fixed ResultSetMetaData.getPrecision()
returning one less than actual on newer versions of MySQL.
ResultSet.getBlob() now returns
null if column value was
null.
Capitalize type names when
capitalizeTypeNames=true is passed in URL or
properties (for WebObjects. (thanks to Anjo Krank)
PreparedStatement.setCharacterStream() now
implemented
Fixed PreparedStatement generating SQL that
would end up with syntax errors for some queries.
Initial transaction isolation level read from database (if available). (thanks to Dmitry Vereshchagin)
Character sets read from database if
useUnicode=true and
characterEncoding is not set. (thanks to
Dmitry Vereshchagin)
Bugs Fixed
Fixed case-sensitive column names in
ResultSet.java.
Fixed PreparedStatement parameter checking.
Bugs Fixed
Fixed ResultSet.getBlob()
ArrayIndex out-of-bounds.
Fixed NPE on
PreparedStatement.executeUpdate() when all
columns have not been set.
Fixed ArrayIndexOutOfBounds when sending
large BLOB queries. (Max size
packet was not being set)
getObject() on ResultSet
correctly does
TINYINT->Byte
and
SMALLINT->Short.
ResultSet has +/-Inf/inf support.
ResultSet.getBoolean() now recognizes
-1 as true.
DataBaseMetaData.getCrossReference() no
longer ArrayIndexOOB.
Added ISOLATION level support to
Connection.setIsolationLevel()
Fixed data parsing of TIMESTAMP
values with 2-digit years.
Added Byte to
PreparedStatement.setObject().
ResultSet.insertRow() works now, even if not
all columns are set (they will be set to
NULL).
Bugs Fixed
Implemented getBigDecimal() without scale
component for JDBC2.
Added ultraDevHack URL parameter, set to
true to enable (broken) Macromedia UltraDev
to use the driver.
Added detection of -/+INF for doubles.
Fixed incorrect detection of
MAX_ALLOWED_PACKET, so sending large blobs
should work now.
Fixed off-by-one error in java.sql.Blob
implementation code.
Faster ASCII string operations.
Fixed composite key problem with updatable result sets.
Bugs Fixed
Fixed some issues with updatability support in
ResultSet when using multiple primary keys.
No escape processing is done on
PreparedStatements anymore per JDBC spec.
Fixed many JDBC-2.0 traversal, positioning bugs, especially with respect to empty result sets. Thanks to Ron Smits, Nick Brook, Cessar Garcia and Carlos Martinez.
DatabaseMetaData.getPrimaryKeys() now works
correctly with respect to key_seq. Thanks to
Brian Slesinsky.
Fixed RSMD.isWritable() returning wrong
value. Thanks to Moritz Maass.
Cleaned up exception handling when driver connects.
Columns that are of type TEXT now
return as Strings when you use
getObject().
Fixes to ResultSet for insertRow() - Thanks to Cesar Garcia
Fix to Driver to recognize JDBC-2.0 by loading a JDBC-2.0 class, instead of relying on JDK version numbers. Thanks to John Baker.
Fixed ResultSet to return correct row numbers
Statement.getUpdateCount() now returns rows matched, instead of rows actually updated, which is more SQL-92 like.
10-29-99
Statement/PreparedStatement.getMoreResults() bug fixed. Thanks to Noel J. Bergman.
Added Short as a type to PreparedStatement.setObject(). Thanks to Jeff Crowder
Driver now automagically configures maximum/preferred packet sizes by querying server.
Autoreconnect code uses fast ping command if server supports it.
Fixed various bugs with respect to packet sizing when reading from the server and when alloc'ing to write to the server.
Now compiles under JDK-1.2. The driver supports both JDK-1.1 and JDK-1.2 at the same time through a core set of classes. The driver will load the appropriate interface classes at runtime by figuring out which JVM version you are using.
Fixes for result sets with all nulls in the first row. (Pointed out by Tim Endres)
Fixes to column numbers in SQLExceptions in ResultSet (Thanks to Blas Rodriguez Somoza)
The database no longer needs to specified to connect. (Thanks to Christian Motschke)
Better Documentation (in progress), in doc/mm.doc/book1.html
DBMD now permits null for a column name pattern (not in spec), which it changes to '%'.
DBMD now has correct types/lengths for getXXX().
ResultSet.getDate(), getTime(), and getTimestamp() fixes. (contributed by Alan Wilken)
EscapeProcessor now handles \{ \} and { or } inside quotation marks correctly. (thanks to Alik for some ideas on how to fix it)
Fixes to properties handling in Connection. (contributed by Juho Tikkala)
ResultSet.getObject() now returns null for NULL columns in the table, rather than bombing out. (thanks to Ben Grosman)
ResultSet.getObject() now returns Strings for types from MySQL that it doesn't know about. (Suggested by Chris Perdue)
Removed DataInput/Output streams, not needed, 1/2 number of method calls per IO operation.
Use default character encoding if one is not specified. This is a work-around for broken JVMs, because according to spec, EVERY JVM must support "ISO8859_1", but they do not.
Fixed Connection to use the platform character encoding instead of "ISO8859_1" if one isn't explicitly set. This fixes problems people were having loading the character- converter classes that didn't always exist (JVM bug). (thanks to Fritz Elfert for pointing out this problem)
Changed MysqlIO to re-use packets where possible to reduce memory usage.
Fixed escape-processor bugs pertaining to {} inside quotation marks.
Fixed character-set support for non-Javasoft JVMs (thanks to many people for pointing it out)
Fixed ResultSet.getBoolean() to recognize 'y' & 'n' as well as '1' & '0' as boolean flags. (thanks to Tim Pizey)
Fixed ResultSet.getTimestamp() to give better performance. (thanks to Richard Swift)
Fixed getByte() for numeric types. (thanks to Ray Bellis)
Fixed DatabaseMetaData.getTypeInfo() for DATE type. (thanks to Paul Johnston)
Fixed EscapeProcessor for "fn" calls. (thanks to Piyush Shah at locomotive.org)
Fixed EscapeProcessor to not do extraneous work if there are no escape codes. (thanks to Ryan Gustafson)
Fixed Driver to parse URLs of the form "jdbc:mysql://host:port" (thanks to Richard Lobb)
Fixed Timestamps for PreparedStatements
Fixed null pointer exceptions in RSMD and RS
Re-compiled with jikes for valid class files (thanks ms!)
Fixed escape processor to deal with unmatched { and } (thanks to Craig Coles)
Fixed escape processor to create more portable (between DATETIME and TIMESTAMP types) representations so that it will work with BETWEEN clauses. (thanks to Craig Longman)
MysqlIO.quit() now closes the socket connection. Before, after many failed connections some OS's would run out of file descriptors. (thanks to Michael Brinkman)
Fixed NullPointerException in Driver.getPropertyInfo. (thanks to Dave Potts)
Fixes to MysqlDefs to allow all *text fields to be retrieved as Strings. (thanks to Chris at Leverage)
Fixed setDouble in PreparedStatement for large numbers to avoid sending scientific notation to the database. (thanks to J.S. Ferguson)
Fixed getScale() and getPrecision() in RSMD. (contrib'd by James Klicman)
Fixed getObject() when field was DECIMAL or NUMERIC (thanks to Bert Hobbs)
DBMD.getTables() bombed when passed a null table-name pattern. Fixed. (thanks to Richard Lobb)
Added check for "client not authorized" errors during connect. (thanks to Hannes Wallnoefer)
Result set rows are now byte arrays. Blobs and Unicode work bidirectonally now. The useUnicode and encoding options are implemented now.
Fixes to PreparedStatement to send binary set by setXXXStream to be sent untouched to the MySQL server.
Fixes to getDriverPropertyInfo().
Changed all ResultSet fields to Strings, this should allow Unicode to work, but your JVM must be able to convert between the character sets. This should also make reading data from the server be a bit quicker, because there is now no conversion from StringBuffer to String.
Changed PreparedStatement.streamToString() to be more efficient (code from Uwe Schaefer).
URL parsing is more robust (throws SQL exceptions on errors rather than NullPointerExceptions)
PreparedStatement now can convert Strings to Time/Date values using setObject() (code from Robert Currey).
IO no longer hangs in Buffer.readInt(), that bug was introduced in 1.1d when changing to all byte-arrays for result sets. (Pointed out by Samo Login)
Fixes to DatabaseMetaData to allow both IBM VA and J-Builder to work. Let me know how it goes. (thanks to Jac Kersing)
Fix to ResultSet.getBoolean() for NULL strings (thanks to Barry Lagerweij)
Beginning of code cleanup, and formatting. Getting ready to branch this off to a parallel JDBC-2.0 source tree.
Added "final" modifier to critical sections in MysqlIO and Buffer to allow compiler to inline methods for speed.
9-29-98
If object references passed to setXXX() in PreparedStatement are null, setNull() is automatically called for you. (Thanks for the suggestion goes to Erik Ostrom)
setObject() in PreparedStatement will now attempt to write a serialized representation of the object to the database for objects of Types.OTHER and objects of unknown type.
Util now has a static method readObject() which given a ResultSet and a column index will re-instantiate an object serialized in the above manner.
Got rid of "ugly hack" in MysqlIO.nextRow(). Rather than catch an exception, Buffer.isLastDataPacket() was fixed.
Connection.getCatalog() and Connection.setCatalog() should work now.
Statement.setMaxRows() works, as well as setting by property maxRows. Statement.setMaxRows() overrides maxRows set using properties or url parameters.
Automatic re-connection is available. Because it has to "ping" the database before each query, it is turned off by default. To use it, pass in "autoReconnect=true" in the connection URL. You may also change the number of reconnect tries, and the initial timeout value using "maxReconnects=n" (default 3) and "initialTimeout=n" (seconds, default 2) parameters. The timeout is an exponential backoff type of timeout; for example, if you have initial timeout of 2 seconds, and maxReconnects of 3, then the driver will timeout 2 seconds, 4 seconds, then 16 seconds between each re-connection attempt.
Fixed handling of blob data in Buffer.java
Fixed bug with authentication packet being sized too small.
The JDBC Driver is now under the LGPL
8-14-98
Fixed Buffer.readLenString() to correctly read data for BLOBS.
Fixed PreparedStatement.stringToStream to correctly read data for BLOBS.
Fixed PreparedStatement.setDate() to not add a day. (above fixes thanks to Vincent Partington)
Added URL parameter parsing (?user=... and so forth).
Big news! New package name. Tim Endres from ICE Engineering is starting a new source tree for GNU GPL'd Java software. He's graciously given me the org.gjt.mm package directory to use, so now the driver is in the org.gjt.mm.mysql package scheme. I'm "legal" now. Look for more information on Tim's project soon.
Now using dynamically sized packets to reduce memory usage when sending commands to the DB.
Small fixes to getTypeInfo() for parameters, and so forth.
DatabaseMetaData is now fully implemented. Let me know if these drivers work with the various IDEs out there. I've heard that they're working with JBuilder right now.
Added JavaDoc documentation to the package.
Package now available in .zip or .tar.gz.
Implemented getTypeInfo(). Connection.rollback() now throws an SQLException per the JDBC spec.
Added PreparedStatement that supports all JDBC API methods for PreparedStatement including InputStreams. Please check this out and let me know if anything is broken.
Fixed a bug in ResultSet that would break some queries that only returned 1 row.
Fixed bugs in DatabaseMetaData.getTables(), DatabaseMetaData.getColumns() and DatabaseMetaData.getCatalogs().
Added functionality to Statement that enables executeUpdate() to store values for IDs that are automatically generated for AUTO_INCREMENT fields. Basically, after an executeUpdate(), look at the SQLWarnings for warnings like "LAST_INSERTED_ID = 'some number', COMMAND = 'your SQL query'". If you are using AUTO_INCREMENT fields in your tables and are executing a lot of executeUpdate()s on one Statement, be sure to clearWarnings() every so often to save memory.
Split MysqlIO and Buffer to separate classes. Some ClassLoaders gave an IllegalAccess error for some fields in those two classes. Now mm.mysql works in applets and all classloaders. Thanks to Joe Ennis <jce@mail.boone.com> for pointing out the problem and working on a fix with me.
Fixed DatabaseMetadata problems in getColumns() and bug in switch statement in the Field constructor. Thanks to Costin Manolache <costin@tdiinc.com> for pointing these out.
Incorporated efficiency changes from Richard Swift
<Richard.Swift@kanatek.ca> in
MysqlIO.java and
ResultSet.java:
We're now 15% faster than gwe's driver.
Started working on DatabaseMetaData.
The following methods are implemented:
getTables()
getTableTypes()
getColumns()
getCatalogs()
The following software may be included in this product: Ant-Contrib
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Licensed under the Apache 1.1 License Agreement, a copy of which is reproduced below.
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Alternately, this acknowlegement may appear in the software itself,
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4. The name Ant-Contrib must not be used to endorse or promote
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permission. For written permission, please contact
ant-contrib-developers@lists.sourceforge.net.
5. Products derived from this software may not be called "Ant-Contrib"
nor may "Ant-Contrib" appear in their names without prior written
permission of the Ant-Contrib project.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.The following software may be included in this product:
Simple Logging Facade for Java (SLF4J) Copyright (c) 2004-2008 QOS.ch All rights reserved. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.