Added: felix/sandbox/uiterlix/dependencymanager/core/src/main/java/org/apache/felix/dm/tracker/ServiceTrackerCustomizer.java URL: http://svn.apache.org/viewvc/felix/sandbox/uiterlix/dependencymanager/core/src/main/java/org/apache/felix/dm/tracker/ServiceTrackerCustomizer.java?rev=1293173&view=auto ============================================================================== --- felix/sandbox/uiterlix/dependencymanager/core/src/main/java/org/apache/felix/dm/tracker/ServiceTrackerCustomizer.java (added) +++ felix/sandbox/uiterlix/dependencymanager/core/src/main/java/org/apache/felix/dm/tracker/ServiceTrackerCustomizer.java Fri Feb 24 10:47:49 2012 @@ -0,0 +1,96 @@ +package org.apache.felix.dm.tracker; +/* + * Copyright (c) OSGi Alliance (2000, 2008). All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +import org.osgi.framework.ServiceReference; + +/** + * The <code>ServiceTrackerCustomizer</code> interface allows a + * <code>ServiceTracker</code> to customize the service objects that are + * tracked. A <code>ServiceTrackerCustomizer</code> is called when a service is + * being added to a <code>ServiceTracker</code>. The + * <code>ServiceTrackerCustomizer</code> can then return an object for the + * tracked service. A <code>ServiceTrackerCustomizer</code> is also called when + * a tracked service is modified or has been removed from a + * <code>ServiceTracker</code>. + * + * <p> + * The methods in this interface may be called as the result of a + * <code>ServiceEvent</code> being received by a <code>ServiceTracker</code>. + * Since <code>ServiceEvent</code>s are synchronously delivered by the + * Framework, it is highly recommended that implementations of these methods do + * not register (<code>BundleContext.registerService</code>), modify ( + * <code>ServiceRegistration.setProperties</code>) or unregister ( + * <code>ServiceRegistration.unregister</code>) a service while being + * synchronized on any object. + * + * <p> + * The <code>ServiceTracker</code> class is thread-safe. It does not call a + * <code>ServiceTrackerCustomizer</code> while holding any locks. + * <code>ServiceTrackerCustomizer</code> implementations must also be + * thread-safe. + * + * @ThreadSafe + * @version $Revision: 5874 $ + */ +public interface ServiceTrackerCustomizer { + /** + * A service is being added to the <code>ServiceTracker</code>. + * + * <p> + * This method is called before a service which matched the search + * parameters of the <code>ServiceTracker</code> is added to the + * <code>ServiceTracker</code>. This method should return the service object + * to be tracked for the specified <code>ServiceReference</code>. The + * returned service object is stored in the <code>ServiceTracker</code> and + * is available from the <code>getService</code> and + * <code>getServices</code> methods. + * + * @param reference The reference to the service being added to the + * <code>ServiceTracker</code>. + * @return The service object to be tracked for the specified referenced + * service or <code>null</code> if the specified referenced service + * should not be tracked. + */ + public Object addingService(ServiceReference reference); + + /** marrs: A service has been added to the ServiceTracker. */ + public void addedService(ServiceReference reference, Object service); + + /** + * A service tracked by the <code>ServiceTracker</code> has been modified. + * + * <p> + * This method is called when a service being tracked by the + * <code>ServiceTracker</code> has had it properties modified. + * + * @param reference The reference to the service that has been modified. + * @param service The service object for the specified referenced service. + */ + public void modifiedService(ServiceReference reference, Object service); + + /** + * A service tracked by the <code>ServiceTracker</code> has been removed. + * + * <p> + * This method is called after a service is no longer being tracked by the + * <code>ServiceTracker</code>. + * + * @param reference The reference to the service that has been removed. + * @param service The service object for the specified referenced service. + */ + public void removedService(ServiceReference reference, Object service); +}
