| /* |
| * 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.proxy; |
| |
| import org.osgi.util.tracker.ServiceTracker; |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.ServiceReference; |
| import org.osgi.framework.Filter; |
| import org.osgi.framework.Constants; |
| import javax.servlet.http.HttpServlet; |
| import javax.servlet.ServletConfig; |
| |
| public final class DispatcherTracker |
| extends ServiceTracker |
| { |
| final static String DEFAULT_FILTER = "(http.felix.dispatcher=*)"; |
| |
| private final ServletConfig config; |
| private HttpServlet dispatcher; |
| |
| public DispatcherTracker(BundleContext context, String filter, ServletConfig config) |
| throws Exception |
| { |
| super(context, createFilter(context, filter), null); |
| this.config = config; |
| } |
| |
| public HttpServlet getDispatcher() |
| { |
| return this.dispatcher; |
| } |
| |
| @Override |
| public Object addingService(ServiceReference ref) |
| { |
| Object service = super.addingService(ref); |
| if (service instanceof HttpServlet) { |
| setDispatcher((HttpServlet)service); |
| } |
| |
| return service; |
| } |
| |
| @Override |
| public void removedService(ServiceReference ref, Object service) |
| { |
| if (service instanceof HttpServlet) { |
| setDispatcher(null); |
| } |
| |
| super.removedService(ref, service); |
| } |
| |
| private void log(String message, Throwable cause) |
| { |
| this.config.getServletContext().log(message, cause); |
| } |
| |
| private void setDispatcher(HttpServlet dispatcher) |
| { |
| destroyDispatcher(); |
| this.dispatcher = dispatcher; |
| initDispatcher(); |
| } |
| |
| private void destroyDispatcher() |
| { |
| if (this.dispatcher == null) { |
| return; |
| } |
| |
| this.dispatcher.destroy(); |
| this.dispatcher = null; |
| } |
| |
| private void initDispatcher() |
| { |
| if (this.dispatcher == null) { |
| return; |
| } |
| |
| try { |
| this.dispatcher.init(this.config); |
| } catch (Exception e) { |
| log("Failed to initialize dispatcher", e); |
| } |
| } |
| |
| private static Filter createFilter(BundleContext context, String filter) |
| throws Exception |
| { |
| StringBuffer str = new StringBuffer(); |
| str.append("(&(").append(Constants.OBJECTCLASS).append("="); |
| str.append(HttpServlet.class.getName()).append(")"); |
| str.append(filter != null ? filter : DEFAULT_FILTER).append(")"); |
| return context.createFilter(str.toString()); |
| } |
| } |