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.logging.log4j.web;
18
19 import javax.servlet.ServletContext;
20 import javax.servlet.ServletContextEvent;
21 import javax.servlet.ServletContextListener;
22
23 /**
24 * In environments older than Servlet 3.0, this initializer is responsible for starting up Log4j logging before anything
25 * else happens in application initialization. In all environments, this shuts down Log4j after the application shuts
26 * down.
27 */
28 public class Log4jServletContextListener implements ServletContextListener {
29
30 private ServletContext servletContext;
31 private Log4jWebLifeCycle initializer;
32
33 @Override
34 public void contextInitialized(final ServletContextEvent event) {
35 this.servletContext = event.getServletContext();
36 this.servletContext.log("Log4jServletContextListener ensuring that Log4j starts up properly.");
37
38 this.initializer = Log4jWebInitializerImpl.getLog4jWebInitializer(this.servletContext);
39 try {
40 this.initializer.start();
41 this.initializer.setLoggerContext(); // the application is just now starting to start up
42 } catch (final IllegalStateException e) {
43 throw new IllegalStateException("Failed to initialize Log4j properly.", e);
44 }
45 }
46
47 @Override
48 public void contextDestroyed(final ServletContextEvent event) {
49 if (this.servletContext == null || this.initializer == null) {
50 throw new IllegalStateException("Context destroyed before it was initialized.");
51 }
52 this.servletContext.log("Log4jServletContextListener ensuring that Log4j shuts down properly.");
53
54 this.initializer.clearLoggerContext(); // the application is finished shutting down now
55 this.initializer.stop();
56 }
57 }