1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.tomcat.websocket.server;
18
19 import javax.servlet.ServletContext;
20 import javax.servlet.ServletContextEvent;
21 import javax.servlet.ServletContextListener;
22
23 /**
24 * In normal usage, this {@link ServletContextListener} does not need to be
25 * explicitly configured as the {@link WsSci} performs all the necessary
26 * bootstrap and installs this listener in the {@link ServletContext}. If the
27 * {@link WsSci} is disabled, this listener must be added manually to every
28 * {@link ServletContext} that uses WebSocket to bootstrap the
29 * {@link WsServerContainer} correctly.
30 */
31 public class WsContextListener implements ServletContextListener {
32
33 @Override
34 public void contextInitialized(ServletContextEvent sce) {
35 ServletContext sc = sce.getServletContext();
36 // Don't trigger WebSocket initialization if a WebSocket Server
37 // Container is already present
38 if (sc.getAttribute(Constants.SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE) == null) {
39 WsSci.init(sce.getServletContext(), false);
40 }
41 }
42
43 @Override
44 public void contextDestroyed(ServletContextEvent sce) {
45 ServletContext sc = sce.getServletContext();
46 Object obj = sc.getAttribute(Constants.SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE);
47 if (obj instanceof WsServerContainer) {
48 ((WsServerContainer) obj).destroy();
49 }
50 }
51 }
52