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.

Version:

$Revision: 1.1 $

Author:

Open Services Gateway Initiative

Method Summary

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

Method Detail

getExportedPackages

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

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

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.