bundles/org.eclipse.osgi/core/framework/org/eclipse/osgi/framework/internal/core/BundleFragment.java - equinox/rt.equinox.framework - Git at Google

 /*******************************************************************************
  * Copyright (c) 2003 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Common Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/cpl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.osgi.framework.internal.core;

 import java.io.IOException;
 import java.net.URL;
 import java.security.PermissionCollection;
 import java.security.ProtectionDomain;
 import org.eclipse.osgi.framework.adaptor.BundleData;
 import org.eclipse.osgi.framework.debug.Debug;
 import org.osgi.framework.*;

 public class BundleFragment extends AbstractBundle {

 	/** The resolved host that this fragment is attached to */
 	protected BundleHost host;

 	/**
 	 * @param bundledata
 	 * @param framework
 	 * @throws BundleException
 	 */
 	public BundleFragment(BundleData bundledata, Framework framework) throws BundleException {
 		super(bundledata, framework);
 		host = null;
 	}

 	/**
 	 * Load the bundle.
 	 * @exception org.osgi.framework.BundleException
 	 */
 	protected void load() throws BundleException {
 		if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
 			if ((state & (INSTALLED)) == 0) {
 				Debug.println("Bundle.load called when state != INSTALLED: " + this); //$NON-NLS-1$
 				Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
 			}
 		}

 		if (framework.isActive()) {
 			SecurityManager sm = System.getSecurityManager();

 			if (sm != null) {
 				PermissionCollection collection = framework.permissionAdmin.createPermissionCollection(this);

 				domain = new ProtectionDomain(null, collection);
 			}

 			try {
 				bundledata.open(); /* make sure the BundleData is open */
 			} catch (IOException e) {
 				throw new BundleException(Msg.formatter.getString("BUNDLE_READ_EXCEPTION"), e); //$NON-NLS-1$
 			}
 		}
 	}

 	/**
 	 * Changes the state from ACTIVE | RESOVED to INSTALLED.  This is called when a
 	 * host gets reloaded or unloaded.
 	 * This method must be called while holding the bundles lock.
 	 *
 	 * @return  true if an exported package is "in use". i.e. it has been imported by a bundle
 	 */
 	protected boolean unresolve() {
 		if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
 			if ((state & (INSTALLED | RESOLVED)) == 0) {
 				Debug.println("Bundle.reload called when state != INSTALLED | RESOLVED: " + this); //$NON-NLS-1$
 				Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
 			}
 		}

 		if (framework.isActive()) {
 			if (host != null) {
 				if (state == RESOLVED) {
 					state = INSTALLED;
 					// publish UNRESOLVED event here.
 					framework.publishBundleEvent(BundleEvent.UNRESOLVED, this);
 					host = null;
 				}
 			}
 		} else {
 			/* close the outgoing jarfile */
 			try {
 				this.bundledata.close();
 			} catch (IOException e) {
 				// Do Nothing
 			}
 		}

 		return (false);
 	}

 	/**
 	 * Reload from a new bundle.
 	 * This method must be called while holding the bundles lock.
 	 *
 	 * @param newBundle Dummy Bundle which contains new data.
 	 * @return  true if an exported package is "in use". i.e. it has been imported by a bundle
 	 * @exception org.osgi.framework.BundleException
 	 */
 	protected boolean reload(AbstractBundle newBundle) throws BundleException {
 		if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
 			if ((state & (INSTALLED | RESOLVED)) == 0) {
 				Debug.println("Bundle.reload called when state != INSTALLED | RESOLVED: " + this); //$NON-NLS-1$
 				Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
 			}
 		}

 		boolean exporting = false;

 		if (framework.isActive()) {
 			if (host != null) {
 				if (state == RESOLVED) {
 					// Unresolving the host will cause the fragment to unresolve
 					exporting = host.unresolve();
 				}
 			}

 		}

 		if (!exporting) {
 			/* close the outgoing jarfile */
 			try {
 				this.bundledata.close();
 			} catch (IOException e) {
 				// Do Nothing
 			}
 		}

 		this.bundledata = newBundle.bundledata;
 		this.bundledata.setBundle(this);
 		return (exporting);
 	}

 	/**
 	 * Refresh the bundle. This is called by Framework.refreshPackages.
 	 * This method must be called while holding the bundles lock.
 	 * this.loader.unimportPackages must have already been called before calling
 	 * this method!
 	 *
 	 * @exception org.osgi.framework.BundleException if an exported package is "in use". i.e. it has been imported by a bundle
 	 */
 	protected void refresh() throws BundleException {
 		if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
 			if ((state & (UNINSTALLED | INSTALLED | RESOLVED)) == 0) {
 				Debug.println("Bundle.refresh called when state != UNINSTALLED | INSTALLED | RESOLVED: " + this); //$NON-NLS-1$
 				Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
 			}
 		}

 		if (state == RESOLVED) {
 			host = null;
 			state = INSTALLED;
 			// Do not publish UNRESOLVED event here.  This is done by caller
 			// to resolve if appropriate.
 		}
 		manifestLocalization = null;
 	}

 	/**
 	 * Unload the bundle.
 	 * This method must be called while holding the bundles lock.
 	 *
 	 * @return  true if an exported package is "in use". i.e. it has been imported by a bundle
 	 */
 	protected boolean unload() {
 		if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
 			if ((state & (UNINSTALLED | INSTALLED | RESOLVED)) == 0) {
 				Debug.println("Bundle.unload called when state != UNINSTALLED | INSTALLED | RESOLVED: " + this); //$NON-NLS-1$
 				Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
 			}
 		}

 		boolean exporting = false;

 		if (framework.isActive()) {
 			if (host != null) {
 				BundleHost resumeHost = host;
 				if (state == RESOLVED) {
 					// Unresolving the host will cause the fragment to unresolve
 					try {
 						exporting = host.unresolve();
 					} catch (BundleException be) {
 						framework.publishFrameworkEvent(FrameworkEvent.ERROR, this, be);
 					}
 				}
 				if (!exporting) {
 					domain = null;
 					try {
 						this.bundledata.close();
 					} catch (IOException e) { // Do Nothing.
 					}
 				}
 				// We must resume the host now that we are unloaded.
 				framework.resumeBundle(resumeHost);
 			}
 		} else {
 			try {
 				this.bundledata.close();
 			} catch (IOException e) { // Do Nothing.
 			}
 		}

 		return (exporting);
 	}

 	/**
 	 * This method loads a class from the bundle.
 	 *
 	 * @param      name     the name of the desired Class.
 	 * @param      checkPermission indicates whether a permission check should be done.
 	 * @return     the resulting Class
 	 * @exception  java.lang.ClassNotFoundException  if the class definition was not found.
 	 */
 	protected Class loadClass(String name, boolean checkPermission) throws ClassNotFoundException {
 		if (checkPermission) {
 			framework.checkAdminPermission();
 			checkValid();
 		}
 		// cannot load a class from a fragment because there is no classloader
 		// associated with fragments.
 		throw new ClassNotFoundException(Msg.formatter.getString("BUNDLE_FRAGMENT_CNFE", name)); //$NON-NLS-1$
 	}

 	/**
 	 * Find the specified resource in this bundle.
 	 *
 	 * This bundle's class loader is called to search for the named resource.
 	 * If this bundle's state is <tt>INSTALLED</tt>, then only this bundle will
 	 * be searched for the specified resource. Imported packages cannot be searched
 	 * when a bundle has not been resolved.
 	 *
 	 * @param name The name of the resource.
 	 * See <tt>java.lang.ClassLoader.getResource</tt> for a description of
 	 * the format of a resource name.
 	 * @return a URL to the named resource, or <tt>null</tt> if the resource could
 	 * not be found or if the caller does not have
 	 * the <tt>AdminPermission</tt>, and the Java Runtime Environment supports permissions.
 	 *
 	 * @exception java.lang.IllegalStateException If this bundle has been uninstalled.
 	 */
 	public URL getResource(String name) {
 		checkValid();
 		// cannot get a resource for a fragment because there is no classloader
 		// associated with fragments.
 		return (null);

 	}

 	/**
 	 * Internal worker to start a bundle.
 	 *
 	 * @param persistent if true persistently record the bundle was started.
 	 */
 	protected void startWorker(boolean persistent) throws BundleException {
 		if (framework.active) {
 			if ((state & (STARTING | ACTIVE)) != 0) {
 				return;
 			}

 			if (state == INSTALLED) {
 				framework.packageAdmin.resolveBundles();

 				if (state != RESOLVED) {
 					throw new BundleException(getResolutionFailureMessage());
 				}
 			}

 			if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
 				Debug.println("Bundle: Active sl = " + framework.startLevelManager.getStartLevel() + "; Bundle " + getBundleId() + " sl = " + getStartLevel()); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 			}

 			if (getStartLevel() <= framework.startLevelManager.getStartLevel()) {
 				if (state == UNINSTALLED) {
 					throw new BundleException(Msg.formatter.getString("BUNDLE_UNINSTALLED_EXCEPTION")); //$NON-NLS-1$
 				}
 				if (framework.active) {
 					state = ACTIVE;

 					if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
 						Debug.println("->started " + this); //$NON-NLS-1$
 					}

 					framework.publishBundleEvent(BundleEvent.STARTED, this);
 				}
 			}
 		}

 		if (persistent) {
 			setStatus(Constants.BUNDLE_STARTED, true);
 		}
 	}

 	/**
 	 * Internal worker to stop a bundle.
 	 *
 	 * @param persistent if true persistently record the bundle was stopped.
 	 */
 	protected void stopWorker(boolean persistent) throws BundleException {
 		if (persistent) {
 			setStatus(Constants.BUNDLE_STARTED, false);
 		}

 		if (framework.active) {
 			if ((state & (STOPPING | RESOLVED | INSTALLED)) != 0) {
 				return;
 			}

 			state = RESOLVED;

 			if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
 				Debug.println("->stopped " + this); //$NON-NLS-1$
 			}

 			framework.publishBundleEvent(BundleEvent.STOPPED, this);
 		}
 	}

 	/**
 	 * Provides a list of {@link ServiceReference}s for the services
 	 * registered by this bundle
 	 * or <code>null</code> if the bundle has no registered
 	 * services.
 	 *
 	 * <p>The list is valid at the time
 	 * of the call to this method, but the framework is a very dynamic
 	 * environment and services can be modified or unregistered at anytime.
 	 *
 	 * @return An array of {@link ServiceReference} or <code>null</code>.
 	 * @exception java.lang.IllegalStateException If the
 	 * bundle has been uninstalled.
 	 * @see ServiceRegistrationImpl
 	 * @see ServiceReference
 	 */
 	public ServiceReference[] getRegisteredServices() {
 		checkValid();
 		// Fragments cannot have a BundleContext and therefore
 		// cannot have any services registered.
 		return null;
 	}

 	/**
 	 * Provides a list of {@link ServiceReference}s for the
 	 * services this bundle is using,
 	 * or <code>null</code> if the bundle is not using any services.
 	 * A bundle is considered to be using a service if the bundle's
 	 * use count for the service is greater than zero.
 	 *
 	 * <p>The list is valid at the time
 	 * of the call to this method, but the framework is a very dynamic
 	 * environment and services can be modified or unregistered at anytime.
 	 *
 	 * @return An array of {@link ServiceReference} or <code>null</code>.
 	 * @exception java.lang.IllegalStateException If the
 	 * bundle has been uninstalled.
 	 * @see ServiceReference
 	 */
 	public ServiceReference[] getServicesInUse() {
 		checkValid();
 		// Fragments cannot have a BundleContext and therefore
 		// cannot have any services in use.
 		return null;
 	}

 	public org.osgi.framework.Bundle getHost() {
 		return host;
 	}

 	public boolean isFragment() {
 		return true;
 	}

 	/**
 	 * Sets the host for this fragment from the list of available
 	 * BundleExporters.  If a matching host cannot be found then a
 	 * resolve Exception is logged.
 	 * @param value the BundleHost to set the host to
 	 */
 	protected boolean setHost(BundleHost value) {
 		host = value;
 		if (host != null) {
 			try {
 				host.attachFragment(this);
 			} catch (BundleException be) {
 				framework.publishFrameworkEvent(FrameworkEvent.ERROR, host, be);
 				return false;
 			}
 		}
 		return true;
 	}

 	public BundleLoader getBundleLoader() {
 		// Fragments cannot have a BundleLoader.
 		return null;
 	}

 	/**
 	 * Return the current context for this bundle.
 	 *
 	 * @return BundleContext for this bundle.
 	 */
 	protected BundleContextImpl getContext() {
 		// Fragments cannot have a BundleContext.
 		return null;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2003 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Common Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/cpl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/

	package org.eclipse.osgi.framework.internal.core;

	import java.io.IOException;
	import java.net.URL;
	import java.security.PermissionCollection;
	import java.security.ProtectionDomain;
	import org.eclipse.osgi.framework.adaptor.BundleData;
	import org.eclipse.osgi.framework.debug.Debug;
	import org.osgi.framework.*;

	public class BundleFragment extends AbstractBundle {

	/** The resolved host that this fragment is attached to */
	protected BundleHost host;

	/**
	* @param bundledata
	* @param framework
	* @throws BundleException
	*/
	public BundleFragment(BundleData bundledata, Framework framework) throws BundleException {
	super(bundledata, framework);
	host = null;
	}

	/**
	* Load the bundle.
	* @exception org.osgi.framework.BundleException
	*/
	protected void load() throws BundleException {
	if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
	if ((state & (INSTALLED)) == 0) {
	Debug.println("Bundle.load called when state != INSTALLED: " + this); //$NON-NLS-1$
	Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
	}
	}

	if (framework.isActive()) {
	SecurityManager sm = System.getSecurityManager();

	if (sm != null) {
	PermissionCollection collection = framework.permissionAdmin.createPermissionCollection(this);

	domain = new ProtectionDomain(null, collection);
	}

	try {
	bundledata.open(); /* make sure the BundleData is open */
	} catch (IOException e) {
	throw new BundleException(Msg.formatter.getString("BUNDLE_READ_EXCEPTION"), e); //$NON-NLS-1$
	}
	}
	}

	/**
	* Changes the state from ACTIVE \| RESOVED to INSTALLED. This is called when a
	* host gets reloaded or unloaded.
	* This method must be called while holding the bundles lock.
	*
	* @return true if an exported package is "in use". i.e. it has been imported by a bundle
	*/
	protected boolean unresolve() {
	if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
	if ((state & (INSTALLED \| RESOLVED)) == 0) {
	Debug.println("Bundle.reload called when state != INSTALLED \| RESOLVED: " + this); //$NON-NLS-1$
	Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
	}
	}

	if (framework.isActive()) {
	if (host != null) {
	if (state == RESOLVED) {
	state = INSTALLED;
	// publish UNRESOLVED event here.
	framework.publishBundleEvent(BundleEvent.UNRESOLVED, this);
	host = null;
	}
	}
	} else {
	/* close the outgoing jarfile */
	try {
	this.bundledata.close();
	} catch (IOException e) {
	// Do Nothing
	}
	}

	return (false);
	}

	/**
	* Reload from a new bundle.
	* This method must be called while holding the bundles lock.
	*
	* @param newBundle Dummy Bundle which contains new data.
	* @return true if an exported package is "in use". i.e. it has been imported by a bundle
	* @exception org.osgi.framework.BundleException
	*/
	protected boolean reload(AbstractBundle newBundle) throws BundleException {
	if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
	if ((state & (INSTALLED \| RESOLVED)) == 0) {
	Debug.println("Bundle.reload called when state != INSTALLED \| RESOLVED: " + this); //$NON-NLS-1$
	Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
	}
	}

	boolean exporting = false;

	if (framework.isActive()) {
	if (host != null) {
	if (state == RESOLVED) {
	// Unresolving the host will cause the fragment to unresolve
	exporting = host.unresolve();
	}
	}

	}

	if (!exporting) {
	/* close the outgoing jarfile */
	try {
	this.bundledata.close();
	} catch (IOException e) {
	// Do Nothing
	}
	}

	this.bundledata = newBundle.bundledata;
	this.bundledata.setBundle(this);
	return (exporting);
	}

	/**
	* Refresh the bundle. This is called by Framework.refreshPackages.
	* This method must be called while holding the bundles lock.
	* this.loader.unimportPackages must have already been called before calling
	* this method!
	*
	* @exception org.osgi.framework.BundleException if an exported package is "in use". i.e. it has been imported by a bundle
	*/
	protected void refresh() throws BundleException {
	if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
	if ((state & (UNINSTALLED \| INSTALLED \| RESOLVED)) == 0) {
	Debug.println("Bundle.refresh called when state != UNINSTALLED \| INSTALLED \| RESOLVED: " + this); //$NON-NLS-1$
	Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
	}
	}

	if (state == RESOLVED) {
	host = null;
	state = INSTALLED;
	// Do not publish UNRESOLVED event here. This is done by caller
	// to resolve if appropriate.
	}
	manifestLocalization = null;
	}

	/**
	* Unload the bundle.
	* This method must be called while holding the bundles lock.
	*
	* @return true if an exported package is "in use". i.e. it has been imported by a bundle
	*/
	protected boolean unload() {
	if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
	if ((state & (UNINSTALLED \| INSTALLED \| RESOLVED)) == 0) {
	Debug.println("Bundle.unload called when state != UNINSTALLED \| INSTALLED \| RESOLVED: " + this); //$NON-NLS-1$
	Debug.printStackTrace(new Exception("Stack trace")); //$NON-NLS-1$
	}
	}

	boolean exporting = false;

	if (framework.isActive()) {
	if (host != null) {
	BundleHost resumeHost = host;
	if (state == RESOLVED) {
	// Unresolving the host will cause the fragment to unresolve
	try {
	exporting = host.unresolve();
	} catch (BundleException be) {
	framework.publishFrameworkEvent(FrameworkEvent.ERROR, this, be);
	}
	}
	if (!exporting) {
	domain = null;
	try {
	this.bundledata.close();
	} catch (IOException e) { // Do Nothing.
	}
	}
	// We must resume the host now that we are unloaded.
	framework.resumeBundle(resumeHost);
	}
	} else {
	try {
	this.bundledata.close();
	} catch (IOException e) { // Do Nothing.
	}
	}

	return (exporting);
	}

	/**
	* This method loads a class from the bundle.
	*
	* @param name the name of the desired Class.
	* @param checkPermission indicates whether a permission check should be done.
	* @return the resulting Class
	* @exception java.lang.ClassNotFoundException if the class definition was not found.
	*/
	protected Class loadClass(String name, boolean checkPermission) throws ClassNotFoundException {
	if (checkPermission) {
	framework.checkAdminPermission();
	checkValid();
	}
	// cannot load a class from a fragment because there is no classloader
	// associated with fragments.
	throw new ClassNotFoundException(Msg.formatter.getString("BUNDLE_FRAGMENT_CNFE", name)); //$NON-NLS-1$
	}

	/**
	* Find the specified resource in this bundle.
	*
	* This bundle's class loader is called to search for the named resource.
	* If this bundle's state is <tt>INSTALLED</tt>, then only this bundle will
	* be searched for the specified resource. Imported packages cannot be searched
	* when a bundle has not been resolved.
	*
	* @param name The name of the resource.
	* See <tt>java.lang.ClassLoader.getResource</tt> for a description of
	* the format of a resource name.
	* @return a URL to the named resource, or <tt>null</tt> if the resource could
	* not be found or if the caller does not have
	* the <tt>AdminPermission</tt>, and the Java Runtime Environment supports permissions.
	*
	* @exception java.lang.IllegalStateException If this bundle has been uninstalled.
	*/
	public URL getResource(String name) {
	checkValid();
	// cannot get a resource for a fragment because there is no classloader
	// associated with fragments.
	return (null);

	}

	/**
	* Internal worker to start a bundle.
	*
	* @param persistent if true persistently record the bundle was started.
	*/
	protected void startWorker(boolean persistent) throws BundleException {
	if (framework.active) {
	if ((state & (STARTING \| ACTIVE)) != 0) {
	return;
	}

	if (state == INSTALLED) {
	framework.packageAdmin.resolveBundles();

	if (state != RESOLVED) {
	throw new BundleException(getResolutionFailureMessage());
	}
	}

	if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
	Debug.println("Bundle: Active sl = " + framework.startLevelManager.getStartLevel() + "; Bundle " + getBundleId() + " sl = " + getStartLevel()); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	}

	if (getStartLevel() <= framework.startLevelManager.getStartLevel()) {
	if (state == UNINSTALLED) {
	throw new BundleException(Msg.formatter.getString("BUNDLE_UNINSTALLED_EXCEPTION")); //$NON-NLS-1$
	}
	if (framework.active) {
	state = ACTIVE;

	if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
	Debug.println("->started " + this); //$NON-NLS-1$
	}

	framework.publishBundleEvent(BundleEvent.STARTED, this);
	}
	}
	}

	if (persistent) {
	setStatus(Constants.BUNDLE_STARTED, true);
	}
	}

	/**
	* Internal worker to stop a bundle.
	*
	* @param persistent if true persistently record the bundle was stopped.
	*/
	protected void stopWorker(boolean persistent) throws BundleException {
	if (persistent) {
	setStatus(Constants.BUNDLE_STARTED, false);
	}

	if (framework.active) {
	if ((state & (STOPPING \| RESOLVED \| INSTALLED)) != 0) {
	return;
	}

	state = RESOLVED;

	if (Debug.DEBUG && Debug.DEBUG_GENERAL) {
	Debug.println("->stopped " + this); //$NON-NLS-1$
	}

	framework.publishBundleEvent(BundleEvent.STOPPED, this);
	}
	}

	/**
	* Provides a list of {@link ServiceReference}s for the services
	* registered by this bundle
	* or <code>null</code> if the bundle has no registered
	* services.
	*
	* <p>The list is valid at the time
	* of the call to this method, but the framework is a very dynamic
	* environment and services can be modified or unregistered at anytime.
	*
	* @return An array of {@link ServiceReference} or <code>null</code>.
	* @exception java.lang.IllegalStateException If the
	* bundle has been uninstalled.
	* @see ServiceRegistrationImpl
	* @see ServiceReference
	*/
	public ServiceReference[] getRegisteredServices() {
	checkValid();
	// Fragments cannot have a BundleContext and therefore
	// cannot have any services registered.
	return null;
	}

	/**
	* Provides a list of {@link ServiceReference}s for the
	* services this bundle is using,
	* or <code>null</code> if the bundle is not using any services.
	* A bundle is considered to be using a service if the bundle's
	* use count for the service is greater than zero.
	*
	* <p>The list is valid at the time
	* of the call to this method, but the framework is a very dynamic
	* environment and services can be modified or unregistered at anytime.
	*
	* @return An array of {@link ServiceReference} or <code>null</code>.
	* @exception java.lang.IllegalStateException If the
	* bundle has been uninstalled.
	* @see ServiceReference
	*/
	public ServiceReference[] getServicesInUse() {
	checkValid();
	// Fragments cannot have a BundleContext and therefore
	// cannot have any services in use.
	return null;
	}

	public org.osgi.framework.Bundle getHost() {
	return host;
	}

	public boolean isFragment() {
	return true;
	}

	/**
	* Sets the host for this fragment from the list of available
	* BundleExporters. If a matching host cannot be found then a
	* resolve Exception is logged.
	* @param value the BundleHost to set the host to
	*/
	protected boolean setHost(BundleHost value) {
	host = value;
	if (host != null) {
	try {
	host.attachFragment(this);
	} catch (BundleException be) {
	framework.publishFrameworkEvent(FrameworkEvent.ERROR, host, be);
	return false;
	}
	}
	return true;
	}

	public BundleLoader getBundleLoader() {
	// Fragments cannot have a BundleLoader.
	return null;
	}

	/**
	* Return the current context for this bundle.
	*
	* @return BundleContext for this bundle.
	*/
	protected BundleContextImpl getContext() {
	// Fragments cannot have a BundleContext.
	return null;
	}
	}