001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017 package org.apache.logging.log4j.web; 018 019 import javax.servlet.ServletContext; 020 import javax.servlet.ServletContextEvent; 021 import javax.servlet.ServletContextListener; 022 023 /** 024 * In environments older than Servlet 3.0, this initializer is responsible for starting up Log4j logging before anything 025 * else happens in application initialization. In all environments, this shuts down Log4j after the application shuts 026 * down. 027 */ 028 public class Log4jServletContextListener implements ServletContextListener { 029 030 private ServletContext servletContext; 031 private Log4jWebLifeCycle initializer; 032 033 @Override 034 public void contextInitialized(final ServletContextEvent event) { 035 this.servletContext = event.getServletContext(); 036 this.servletContext.log("Log4jServletContextListener ensuring that Log4j starts up properly."); 037 038 this.initializer = Log4jWebInitializerImpl.getLog4jWebInitializer(this.servletContext); 039 try { 040 this.initializer.start(); 041 this.initializer.setLoggerContext(); // the application is just now starting to start up 042 } catch (final IllegalStateException e) { 043 throw new IllegalStateException("Failed to initialize Log4j properly.", e); 044 } 045 } 046 047 @Override 048 public void contextDestroyed(final ServletContextEvent event) { 049 if (this.servletContext == null || this.initializer == null) { 050 throw new IllegalStateException("Context destroyed before it was initialized."); 051 } 052 this.servletContext.log("Log4jServletContextListener ensuring that Log4j shuts down properly."); 053 054 this.initializer.clearLoggerContext(); // the application is finished shutting down now 055 this.initializer.stop(); 056 } 057 }