1 /* 2 * $Header: /cvshome/build/org.osgi.framework/src/org/osgi/framework/ServiceListener.java,v 1.15 2007/02/20 00:16:30 hargrave Exp $ 3 * 4 * Copyright (c) OSGi Alliance (2000, 2007). All Rights Reserved. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 package org.osgi.framework; 20 21 import java.util.EventListener; 22 23 /** 24 * A <code>ServiceEvent</code> listener. <code>ServiceListener</code> is a 25 * listener interface that may be implemented by a bundle developer. When a 26 * <code>ServiceEvent</code> is fired, it is synchronously delivered to a 27 * <code>ServiceListener</code>. The Framework may deliver 28 * <code>ServiceEvent</code> objects to a <code>ServiceListener</code> out 29 * of order and may concurrently call and/or reenter a 30 * <code>ServiceListener</code>. 31 * 32 * <p> 33 * A <code>ServiceListener</code> object is registered with the Framework 34 * using the <code>BundleContext.addServiceListener</code> method. 35 * <code>ServiceListener</code> objects are called with a 36 * <code>ServiceEvent</code> object when a service is registered, modified, or 37 * is in the process of unregistering. 38 * 39 * <p> 40 * <code>ServiceEvent</code> object delivery to <code>ServiceListener</code> 41 * objects is filtered by the filter specified when the listener was registered. 42 * If the Java Runtime Environment supports permissions, then additional 43 * filtering is done. <code>ServiceEvent</code> objects are only delivered to 44 * the listener if the bundle which defines the listener object's class has the 45 * appropriate <code>ServicePermission</code> to get the service using at 46 * least one of the named classes under which the service was registered. 47 * 48 * <p> 49 * <code>ServiceEvent</code> object delivery to <code>ServiceListener</code> 50 * objects is further filtered according to package sources as defined in 51 * {@link ServiceReference#isAssignableTo(Bundle, String)}. 52 * 53 * @see ServiceEvent 54 * @see ServicePermission 55 * @ThreadSafe 56 * @version $Revision: 1.15 $ 57 */ 58 59 public interface ServiceListener extends EventListener { 60 /** 61 * Receives notification that a service has had a lifecycle change. 62 * 63 * @param event The <code>ServiceEvent</code> object. 64 */ 65 public void serviceChanged(ServiceEvent event); 66 } 67