OSGi Service Platform
Release 3

org.osgi.service.packageadmin
Interface PackageAdmin


public interface PackageAdmin

Framework service which allows bundle programmers to inspect the packages exported in the Framework and eagerly update or uninstall bundles. If present, there will only be a single instance of this service registered with the Framework.

The term exported package (and the corresponding interface ExportedPackage)refers to a package that has actually been exported (as opposed to one that is available for export).

The information about exported packages returned by this service is valid only until the next time refreshPackages(org.osgi.framework.Bundle[])is called. If an ExportedPackage object becomes stale, (that is, the package it references has been updated or removed as a result of calling PackageAdmin.refreshPackages()), its getName() and getSpecificationVersion() continue to return their old values, isRemovalPending() returns true, and getExportingBundle() and getImportingBundles() return null.


Field Summary
static int BUNDLE_TYPE_FRAGMENT
          The bundle is a fragment bundle.
 
Method Summary
 Bundle[] getBundles(java.lang.String symbolicName, java.lang.String versionRange)
          Returns the bundles with the specified symbolic name within the specified version range.
 int getBundleType(Bundle bundle)
          Returns the special type of the specified bundle.
 ExportedPackage getExportedPackage(java.lang.String name)
          Gets the ExportedPackage object with the specified package name.
 ExportedPackage[] getExportedPackages(Bundle bundle)
          Gets the packages exported by the specified bundle.
 Bundle[] getFragments(Bundle bundle)
          Returns an array of attached fragment bundles for the specified bundle.
 Bundle[] getHosts(Bundle bundle)
          Returns an array of host bundles to which the specified fragment bundle is attached or null if the specified bundle is not attached to a host or is not a fragment bundle.
 ProvidingBundle[] getProvidingBundles(java.lang.String symbolicName)
          Returns an array of ProvidingBundles for each resolved bundle with the specified symbolic name.
 void refreshPackages(Bundle[] bundles)
          Forces the update (replacement) or removal of packages exported by the specified bundles.
 boolean resolveBundles(Bundle[] bundles)
          Resolve the specified bundles.
 

Field Detail

BUNDLE_TYPE_FRAGMENT

public static final int BUNDLE_TYPE_FRAGMENT
The bundle is a fragment bundle.

The value of BUNDLE_TYPE_FRAGMENT is 0x00000001.

Since:
1.2 EXPERIMENTAL
Method Detail

getExportedPackages

public ExportedPackage[] getExportedPackages(Bundle bundle)
Gets the packages exported by the specified bundle.
Parameters:
bundle - The bundle whose exported packages are to be returned, or null if all the packages currently exported in the Framework are to be returned. If the specified bundle is the system bundle (that is, the bundle with id zero), this method returns all the packages on the system classpath whose name does not start with "java.". In an environment where the exhaustive list of packages on the system classpath is not known in advance, this method will return all currently known packages on the system classpath, that is, all packages on the system classpath that contains one or more classes that have been loaded.
Returns:
The array of packages exported by the specified bundle, or null if the specified bundle has not exported any packages.

getExportedPackage

public ExportedPackage getExportedPackage(java.lang.String name)
Gets the ExportedPackage object with the specified package name. All exported packages will be checked for the specified name. In an environment where the exhaustive list of packages on the system classpath is not known in advance, this method attempts to see if the named package is on the system classpath. This means that this method may discover an ExportedPackage object that was not present in the list returned by a prior call to getExportedPackages().
Parameters:
name - The name of the exported package to be returned.
Returns:
The exported package with the specified name, or null if no expored package with that name exists.

refreshPackages

public void refreshPackages(Bundle[] bundles)
Forces the update (replacement) or removal of packages exported by the specified bundles.

If no bundles are specified, this method will update or remove any packages exported by any bundles that were previously updated or uninstalled since the last call to this method. The technique by which this is accomplished may vary among different Framework implementations. One permissible implementation is to stop and restart the Framework.

This method returns to the caller immediately and then performs the following steps in its own thread:

  1. Compute a graph of bundles starting with the specified bundles. If no bundles are specified, compute a graph of bundles starting with previously updated or uninstalled ones. Add to the graph any bundle that imports a package that is currently exported by a bundle in the graph. The graph is fully constructed when there is no bundle outside the graph that imports a package from a bundle in the graph. The graph may contain UNINSTALLED bundles that are currently still exporting packages.
  2. Each bundle in the graph that is in the ACTIVE state will be stopped as described in the Bundle.stop method.
  3. Each bundle in the graph that is in the RESOLVED state is moved to the INSTALLED state. The effect of this step is that bundles in the graph are no longer RESOLVED.
  4. Each bundle in the graph that is in the UNINSTALLED state is removed from the graph and is now completely removed from the Framework.
  5. Each bundle in the graph that was in the ACTIVE state prior to Step 2 is started as described in the Bundle.start method, causing all bundles required for the restart to be resolved. It is possible that, as a result of the previous steps, packages that were previously exported no longer are. Therefore, some bundles may be unresolvable until another bundle offering a compatible package for export has been installed in the Framework.
  6. A framework event of type FrameworkEvent.PACKAGES_REFRESHED is broadcast.

For any exceptions that are thrown during any of these steps, a FrameworkEvent of type ERROR is broadcast, containing the exception. The source bundle for these events should be the specific bundle to which the exception is related. If no specific bundle can be associated with the exception then the System Bundle must be used as the source bundle for the event.

Parameters:
bundles - the bundles whose exported packages are to be updated or removed, or null for all previously updated or uninstalled bundles.
Throws:
java.lang.SecurityException - if the caller does not have the AdminPermission and the Java runtime environment supports permissions.

resolveBundles

public boolean resolveBundles(Bundle[] bundles)
Resolve the specified bundles. The Framework must attempt to resolve the specified bundles that are unresolved. Additional bundles that are not included in the specified bundles may be resolved as a result of calling this method. A permissible implementation of this method is to attempt to resolve all unresolved bundles installed in the framework.

If null is specified then the Framework will attempt to resolve all unresolved bundles. This method must not cause any bundle to be refreshed, stopped, or started. This method will not return until the operation has completed.

Parameters:
bundles - The bundles to resolve or null to resolve all unresolved bundles installed in the Framework.
Returns:
true if all specified bundles are resolved;
Since:
1.2 EXPERIMENTAL

getProvidingBundles

public ProvidingBundle[] getProvidingBundles(java.lang.String symbolicName)
Returns an array of ProvidingBundles for each resolved bundle with the specified symbolic name. If the symbolic name argument is null then all resolved bundles with symbolic names are returned.
Parameters:
symbolicName - The symbolic name of the desired bundles or null for all bundles with symbolic names.
Returns:
An array of ProvidingBundles with the specified symbolic name or null if no resolved bundles exist with that symbolic name.
Since:
1.2 EXPERIMENTAL

getBundles

public Bundle[] getBundles(java.lang.String symbolicName,
                           java.lang.String versionRange)
Returns the bundles with the specified symbolic name within the specified version range. If no bundles are installed that have the specified symbolic name, then null is returned. If a version range is specified, then only the bundles that have the specified symbolic name and belong to the specified version range are returned. The returned bundles are ordered by version in descending version order so that the first element of the array contains the bundle with the highest version.
Parameters:
symbolicName - The symbolic name of the desired bundles.
versionRange - The version range of the desired bundles, or null if all versions are desired.
Returns:
An array of bundles with the specified name belonging to the specified version range ordered in descending version order, or null if no bundles are found.
Since:
1.2 EXPERIMENTAL
See Also:
Constants.BUNDLE_VERSION_ATTRIBUTE

getFragments

public Bundle[] getFragments(Bundle bundle)
Returns an array of attached fragment bundles for the specified bundle. If the specified bundle is a fragment then null is returned. If no fragments are attached to the specified bundle then null is returned.
Parameters:
bundle - The bundle whose attached fragment bundles are to be returned.
Returns:
An array of fragment bundles or null if the bundle does not have any attached fragment bundles.
Since:
1.2 EXPERIMENTAL

getHosts

public Bundle[] getHosts(Bundle bundle)
Returns an array of host bundles to which the specified fragment bundle is attached or null if the specified bundle is not attached to a host or is not a fragment bundle.
Parameters:
bundle - The bundle whose host bundles are to be returned.
Returns:
An array of host bundles or null if the bundle does not have any host bundles.
Since:
1.2 EXPERIMENTAL

getBundleType

public int getBundleType(Bundle bundle)
Returns the special type of the specified bundle. The bundle type values are: A bundle may be more than one type at a time. A type code is used to identify the bundle type for future extendability.

If a bundle is not one or more of the defined types then 0x00000000 is returned.

Returns:
The special type of the bundle.
Since:
1.2 EXPERIMENTAL

OSGi Service Platform
Release 3

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