net.sf.saxon.value
Class StringValue

java.lang.Object
  extended bynet.sf.saxon.value.Value
      extended bynet.sf.saxon.value.AtomicValue
          extended bynet.sf.saxon.value.StringValue
All Implemented Interfaces:
Expression, Item, java.io.Serializable, ValueRepresentation
Direct Known Subclasses:
AnyURIValue, RestrictedStringValue, UntypedAtomicValue

public class StringValue
extends AtomicValue

An atomic value of type xs:string

See Also:
Serialized Form

Nested Class Summary
 class StringValue.CharacterIterator
          CharacterIterator is used to iterate over the characters in a string, returning them as integers representing the Unicode code-point.
 
Field Summary
static StringValue EMPTY_STRING
           
protected  int length
           
static StringValue SINGLE_SPACE
           
protected  java.lang.CharSequence value
           
 
Fields inherited from interface net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
 
Constructor Summary
protected StringValue()
          Protected constructor for use by subtypes
  StringValue(java.lang.CharSequence value)
          Constructor.
 
Method Summary
 AtomicValue convertPrimitive(BuiltInAtomicType requiredType, boolean validate)
          Convert a value to another primitive data type, with control over how validation is handled.
 java.lang.Object convertToJava(java.lang.Class target, XPathContext context)
          Convert to Java object (for passing to external functions)
 boolean effectiveBooleanValue(XPathContext context)
          Get the effective boolean value of the value
 boolean equals(java.lang.Object other)
          Determine if two StringValues are equal, according to XML Schema rules.
static int[] expand(java.lang.CharSequence s)
          Expand a string containing surrogate pairs into an array of 32-bit characters
 ItemType getItemType()
          Return the type of the expression
 int getStringLength()
          Get the length of this string, as defined in XPath.
static int getStringLength(java.lang.CharSequence s)
          Get the length of a string, as defined in XPath.
 java.lang.String getStringValue()
          Get the string value as a String
 java.lang.CharSequence getStringValueCS()
          Get the value of the item as a CharSequence.
 int hashCode()
          Return a hash code to support the equals() function
 SequenceIterator iterateCharacters()
          Iterate over a string, returning a sequence of integers representing the Unicode code-point values
 java.lang.String toString()
          Get string value.
 
Methods inherited from class net.sf.saxon.value.AtomicValue
checkPermittedContents, convert, convert, display, evaluateAsString, evaluateItem, getCardinality, getComponent, getImplementationMethod, getLength, getPrimitiveValue, getTypedValue, hasBuiltInType, iterate, process
 
Methods inherited from class net.sf.saxon.value.Value
analyze, asItem, asValue, collapseWhitespace, convert, convertJavaObjectToXPath, getDependencies, getIterator, getParentExpression, getSpecialProperties, itemAt, iterateSubExpressions, makeQNameValue, normalizeWhitespace, promote, simplify, stringToNumber, trimWhitespace
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

EMPTY_STRING

public static final StringValue EMPTY_STRING

SINGLE_SPACE

public static final StringValue SINGLE_SPACE

value

protected java.lang.CharSequence value

length

protected int length
Constructor Detail

StringValue

protected StringValue()
Protected constructor for use by subtypes


StringValue

public StringValue(java.lang.CharSequence value)
Constructor. Note that although a StringValue may wrap any kind of CharSequence (usually a String, but it can also be, for example, a StringBuffer), the caller is responsible for ensuring that the value is immutable.

Parameters:
value - the String value. Null is taken as equivalent to "".
Method Detail

getStringValue

public final java.lang.String getStringValue()
Get the string value as a String

Specified by:
getStringValue in interface Item
Specified by:
getStringValue in class AtomicValue

getStringValueCS

public final java.lang.CharSequence getStringValueCS()
Get the value of the item as a CharSequence. This is in some cases more efficient than the version of the method that returns a String.

Specified by:
getStringValueCS in interface Item
Overrides:
getStringValueCS in class AtomicValue

convertPrimitive

public AtomicValue convertPrimitive(BuiltInAtomicType requiredType,
                                    boolean validate)
Convert a value to another primitive data type, with control over how validation is handled.

Specified by:
convertPrimitive in class AtomicValue
Parameters:
requiredType - type code of the required atomic type
validate - true if validation is required. If set to false, the caller guarantees that the value is valid for the target data type, and that further validation is therefore not required. Note that a validation failure may be reported even if validation was not requested.
Returns:
the result of the conversion, if successful. If unsuccessful, the value returned will be an ErrorValue. The caller must check for this condition. No exception is thrown, instead the exception will be encapsulated within the ErrorValue.

getItemType

public ItemType getItemType()
Return the type of the expression

Specified by:
getItemType in interface Expression
Overrides:
getItemType in class Value
Returns:
Type.STRING (always)

getStringLength

public int getStringLength()
Get the length of this string, as defined in XPath. This is not the same as the Java length, as a Unicode surrogate pair counts as a single character


getStringLength

public static int getStringLength(java.lang.CharSequence s)
Get the length of a string, as defined in XPath. This is not the same as the Java length, as a Unicode surrogate pair counts as a single character.

Parameters:
s - The string whose length is required

iterateCharacters

public SequenceIterator iterateCharacters()
Iterate over a string, returning a sequence of integers representing the Unicode code-point values


expand

public static int[] expand(java.lang.CharSequence s)
Expand a string containing surrogate pairs into an array of 32-bit characters


equals

public boolean equals(java.lang.Object other)
Determine if two StringValues are equal, according to XML Schema rules. (This method is not used for XPath comparisons, which are always under the control of a collation.)

Overrides:
equals in class Value
Throws:
java.lang.ClassCastException - if the values are not comparable

hashCode

public int hashCode()
Description copied from class: Value
Return a hash code to support the equals() function

Overrides:
hashCode in class Value

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)
                              throws XPathException
Description copied from class: AtomicValue
Get the effective boolean value of the value

Specified by:
effectiveBooleanValue in interface Expression
Overrides:
effectiveBooleanValue in class AtomicValue
Parameters:
context - the evaluation context (not used in this implementation)
Returns:
true, unless the value is boolean false, numeric zero, or zero-length string
Throws:
XPathException

convertToJava

public java.lang.Object convertToJava(java.lang.Class target,
                                      XPathContext context)
                               throws XPathException
Convert to Java object (for passing to external functions)

Overrides:
convertToJava in class Value
Throws:
XPathException

toString

public java.lang.String toString()
Description copied from class: AtomicValue
Get string value. In general toString() for an atomic value displays the value as it would be written in XPath: that is, as a literal if available, or as a call on a constructor function otherwise.

Overrides:
toString in class AtomicValue