| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.felix.http.base.internal.whiteboard.tracker; |
| |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.apache.felix.http.base.internal.runtime.WhiteboardServiceInfo; |
| import org.apache.felix.http.base.internal.whiteboard.WhiteboardManager; |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.Constants; |
| import org.osgi.framework.InvalidSyntaxException; |
| import org.osgi.framework.ServiceReference; |
| import org.osgi.util.tracker.ServiceTracker; |
| |
| /** |
| * Service tracker for all whiteboard services except servlet context helper. |
| * This tracker does not get/unget the service objects itself, but just forwards the service reference |
| * by creating an info data object. Each sub class creates a different |
| * data object. |
| */ |
| public abstract class WhiteboardServiceTracker<T> extends ServiceTracker<T, ServiceReference<T>> |
| { |
| /** Map containing all info objects reported from the trackers. */ |
| private final Map<Long, WhiteboardServiceInfo<T>> allInfos = new ConcurrentHashMap<Long, WhiteboardServiceInfo<T>>(); |
| |
| private static org.osgi.framework.Filter createFilter(final BundleContext btx, final String expr) |
| { |
| try |
| { |
| return btx.createFilter(expr); |
| } |
| catch ( final InvalidSyntaxException ise) |
| { |
| // we can safely ignore it as the filter is a constant |
| } |
| return null; // we never get here - and if we get an NPE which is fine |
| } |
| |
| /** The manager is called for each added/removed reference. */ |
| private final WhiteboardManager contextManager; |
| |
| /** |
| * Create a new tracker |
| * @param contextManager The context manager |
| * @param bundleContext The bundle context. |
| * @param filterExpr The filter expression for the services to track |
| */ |
| public WhiteboardServiceTracker(final WhiteboardManager contextManager, |
| final BundleContext bundleContext, final String filterExpr) |
| { |
| super(bundleContext, createFilter(bundleContext, filterExpr), null); |
| this.contextManager = contextManager; |
| } |
| |
| @Override |
| public void close() { |
| super.close(); |
| this.allInfos.clear(); |
| } |
| |
| @Override |
| public final ServiceReference<T> addingService(final ServiceReference<T> ref) |
| { |
| this.added(ref); |
| return ref; |
| } |
| |
| @Override |
| public final void modifiedService(final ServiceReference<T> ref, final ServiceReference<T> service) |
| { |
| this.modified(ref); |
| } |
| |
| @Override |
| public final void removedService(final ServiceReference<T> ref, final ServiceReference<T> service) |
| { |
| this.removed(ref); |
| } |
| |
| private void modified(final ServiceReference<T> ref) |
| { |
| removed(ref); |
| added(ref); |
| } |
| |
| private void added(final ServiceReference<T> ref) |
| { |
| final WhiteboardServiceInfo<T> info = this.getServiceInfo(ref); |
| if ( this.contextManager.addWhiteboardService(info) ) |
| { |
| this.allInfos.put((Long)ref.getProperty(Constants.SERVICE_ID), info); |
| } |
| } |
| |
| private void removed(final ServiceReference<T> ref) |
| { |
| final WhiteboardServiceInfo<T> info = this.allInfos.remove(ref.getProperty(Constants.SERVICE_ID)); |
| if ( info != null ) |
| { |
| this.contextManager.removeWhiteboardService(info); |
| } |
| } |
| |
| /** |
| * Implemented by sub classes to create the correct whiteboard service info object. |
| * @param ref The service reference |
| * @return A whiteboard service info |
| */ |
| protected abstract WhiteboardServiceInfo<T> getServiceInfo(final ServiceReference<T> ref); |
| } |