WsContextListener.java

  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. import javax.servlet.ServletContext;
  19. import javax.servlet.ServletContextEvent;
  20. import javax.servlet.ServletContextListener;

  21. /**
  22.  * In normal usage, this {@link ServletContextListener} does not need to be explicitly configured as the {@link WsSci}
  23.  * performs all the necessary bootstrap and installs this listener in the {@link ServletContext}. If the {@link WsSci}
  24.  * is disabled, this listener must be added manually to every {@link ServletContext} that uses WebSocket to bootstrap
  25.  * the {@link WsServerContainer} correctly.
  26.  */
  27. public class WsContextListener implements ServletContextListener {

  28.     @Override
  29.     public void contextInitialized(ServletContextEvent sce) {
  30.         ServletContext sc = sce.getServletContext();
  31.         // Don't trigger WebSocket initialization if a WebSocket Server
  32.         // Container is already present
  33.         if (sc.getAttribute(Constants.SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE) == null) {
  34.             WsSci.init(sce.getServletContext(), false);
  35.         }
  36.     }

  37.     @Override
  38.     public void contextDestroyed(ServletContextEvent sce) {
  39.         ServletContext sc = sce.getServletContext();
  40.         Object obj = sc.getAttribute(Constants.SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE);
  41.         if (obj instanceof WsServerContainer) {
  42.             ((WsServerContainer) obj).destroy();
  43.         }
  44.     }
  45. }