/* | |
* $Header: /cvshome/build/org.osgi.util.tracker/src/org/osgi/util/tracker/ServiceTrackerCustomizer.java,v 1.9 2006/03/14 01:20:01 hargrave Exp $ | |
* | |
* Copyright (c) OSGi Alliance (2000, 2005). 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. | |
*/ | |
package org.osgi.util.tracker; | |
import org.osgi.framework.ServiceReference; | |
/** | |
* The <code>ServiceTrackerCustomizer</code> interface allows a | |
* <code>ServiceTracker</code> object to customize the service objects that are | |
* tracked. The <code>ServiceTrackerCustomizer</code> object is called when a | |
* service is being added to the <code>ServiceTracker</code> object. The | |
* <code>ServiceTrackerCustomizer</code> can then return an object for the tracked | |
* service. The <code>ServiceTrackerCustomizer</code> object is also called when a | |
* tracked service is modified or has been removed from the | |
* <code>ServiceTracker</code> object. | |
* | |
* <p> | |
* The methods in this interface may be called as the result of a | |
* <code>ServiceEvent</code> being received by a <code>ServiceTracker</code> object. | |
* 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. | |
* | |
* @version $Revision: 1.9 $ | |
*/ | |
public interface ServiceTrackerCustomizer { | |
/** | |
* A service is being added to the <code>ServiceTracker</code> object. | |
* | |
* <p> | |
* This method is called before a service which matched the search | |
* parameters of the <code>ServiceTracker</code> object is added to it. This | |
* method should return the service object to be tracked for this | |
* <code>ServiceReference</code> object. The returned service object is stored | |
* in the <code>ServiceTracker</code> object and is available from the | |
* <code>getService</code> and <code>getServices</code> methods. | |
* | |
* @param reference Reference to service being added to the | |
* <code>ServiceTracker</code> object. | |
* @return The service object to be tracked for the | |
* <code>ServiceReference</code> object or <code>null</code> if the | |
* <code>ServiceReference</code> object should not be tracked. | |
*/ | |
public Object addingService(ServiceReference reference); | |
/** | |
* A service tracked by the <code>ServiceTracker</code> object has been | |
* modified. | |
* | |
* <p> | |
* This method is called when a service being tracked by the | |
* <code>ServiceTracker</code> object has had it properties modified. | |
* | |
* @param reference Reference to service that has been modified. | |
* @param service The service object for the modified service. | |
*/ | |
public void modifiedService(ServiceReference reference, | |
Object service); | |
/** | |
* A service tracked by the <code>ServiceTracker</code> object has been | |
* removed. | |
* | |
* <p> | |
* This method is called after a service is no longer being tracked by the | |
* <code>ServiceTracker</code> object. | |
* | |
* @param reference Reference to service that has been removed. | |
* @param service The service object for the removed service. | |
*/ | |
public void removedService(ServiceReference reference, | |
Object service); | |
} |