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 */ 017package org.apache.logging.log4j.core.web; 018 019import javax.servlet.ServletContext; 020import javax.servlet.ServletContextEvent; 021import javax.servlet.ServletContextListener; 022import javax.servlet.UnavailableException; 023 024/** 025 * In environments older than Servlet 3.0, this initializer is responsible for starting up Log4j logging before anything 026 * else happens in application initialization. In all environments, this shuts down Log4j after the application shuts 027 * down. 028 */ 029public class Log4jServletContextListener implements ServletContextListener { 030 031 private ServletContext servletContext; 032 private Log4jWebInitializer initializer; 033 034 @Override 035 public void contextInitialized(final ServletContextEvent event) { 036 this.servletContext = event.getServletContext(); 037 this.servletContext.log("Log4jServletContextListener ensuring that Log4j starts up properly."); 038 039 this.initializer = Log4jWebInitializerImpl.getLog4jWebInitializer(this.servletContext); 040 try { 041 this.initializer.initialize(); 042 this.initializer.setLoggerContext(); // the application is just now starting to start up 043 } catch (final UnavailableException e) { 044 throw new RuntimeException("Failed to initialize Log4j properly.", e); 045 } 046 } 047 048 @Override 049 public void contextDestroyed(final ServletContextEvent event) { 050 if (this.servletContext == null || this.initializer == null) { 051 throw new IllegalStateException("Context destroyed before it was initialized."); 052 } 053 this.servletContext.log("Log4jServletContextListener ensuring that Log4j shuts down properly."); 054 055 this.initializer.clearLoggerContext(); // the application is finished shutting down now 056 this.initializer.deinitialize(); 057 } 058}