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1   /**
2    *  Copyright 2003-2007 Greg Luck
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License");
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License.
15   */
16  
17  package net.sf.ehcache.constructs.web;
18  
19  import net.sf.ehcache.CacheManager;
20  
21  import javax.servlet.ServletContextEvent;
22  import javax.servlet.ServletContextListener;
23  
24  import org.apache.commons.logging.Log;
25  import org.apache.commons.logging.LogFactory;
26  
27  import java.util.List;
28  
29  /**
30   * A ServletContextListener that shutsdown CacheManager. Use this when you want to shutdown
31   * ehcache automatically when the web application is shutdown. If the web application is in
32   * a VM which is being shutdown, the ehcache shutdown hooks will do the work and this class
33   * is not required.
34   * <p/>
35   * To receive notification events, this class must be configured in the deployment descriptor for the web application.
36   * To do so, add the following to web.xml in your web application:
37   * <pre>
38   * &lt;listener&gt;
39   *      <listener-class>net.sf.ehcache.constructs.web.ShutdownListener</listener-class>
40   * &lt;/listener&gt;
41   * <p/>
42   * </pre>
43   *
44   * @author Daniel Wiell
45   * @author Greg Luck
46   * @version $Id: ShutdownListener.java 512 2007-07-10 09:18:45Z gregluck $
47   */
48  public class ShutdownListener implements ServletContextListener {
49  
50      private static final Log LOG = LogFactory.getLog(ShutdownListener.class.getName());
51  
52      /**
53       * Notification that the web application is ready to process requests.
54       *
55       * @param servletContextEvent
56       */
57      public void contextInitialized(ServletContextEvent servletContextEvent) {
58          //nothing required
59      }
60  
61      /**
62       * Notification that the servlet context is about to be shut down.
63       * <p/>
64       * Shuts down all cache managers known to {@link CacheManager#ALL_CACHE_MANAGERS}
65       *
66       * @param servletContextEvent
67       */
68      public void contextDestroyed(ServletContextEvent servletContextEvent) {
69          List knownCacheManagers = CacheManager.ALL_CACHE_MANAGERS;
70          if (LOG.isDebugEnabled()) {
71              LOG.debug("Shutting down " + knownCacheManagers.size() + " CacheManagers.");
72          }
73          while (!knownCacheManagers.isEmpty()) {
74              ((CacheManager) CacheManager.ALL_CACHE_MANAGERS.get(0)).shutdown();
75          }
76      }
77  }