| 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); |
| } |