Java tutorial
/* * RED5 Open Source Media Server - https://github.com/Red5/ * * Copyright 2006-2016 by respective authors (see below). All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.red5.logging; import java.net.URL; import java.nio.file.Files; import java.nio.file.Paths; import javax.servlet.ServletContext; import javax.servlet.ServletContextEvent; import javax.servlet.ServletContextListener; import org.slf4j.Logger; import org.springframework.web.context.ConfigurableWebApplicationContext; import org.springframework.web.context.WebApplicationContext; import ch.qos.logback.classic.LoggerContext; import ch.qos.logback.classic.selector.ContextSelector; /** * A servlet context listener that puts this contexts LoggerContext into a static map of logger contexts within an overall singleton log context selector. * * To use it, add the following line to a web.xml file * * <pre> * <listener> * <listener-class>org.red5.logging.ContextLoggingListener</listener-class> * </listener> * </pre> * * @author Paul Gregoire (mondain@gmail.com) */ public class ContextLoggingListener implements ServletContextListener { public void contextInitialized(ServletContextEvent event) { ServletContext servletContext = event.getServletContext(); String contextName = servletContext.getContextPath().replaceAll("/", ""); if ("".equals(contextName)) { contextName = "root"; } System.out.printf("Context init: %s%n", contextName); ConfigurableWebApplicationContext appctx = (ConfigurableWebApplicationContext) servletContext .getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE); if (appctx != null) { System.out.printf( "ConfigurableWebApplicationContext is not null in ContextLoggingListener for: %s, this indicates a misconfiguration or load order problem%n", contextName); } try { // get the selector ContextSelector selector = Red5LoggerFactory.getContextSelector(); // get the logger context for this servlet / app context by name URL url = servletContext.getResource(String.format("/WEB-INF/classes/logback-%s.xml", contextName)); if (url != null && Files.exists(Paths.get(url.toURI()))) { System.out.printf("Context logger config found: %s%n", url.toURI()); } else { url = servletContext.getResource("/WEB-INF/classes/logback.xml"); if (url != null && Files.exists(Paths.get(url.toURI()))) { System.out.printf("Context logger config found: %s%n", url.toURI()); } } // get the logger context for the servlet context LoggerContext loggerContext = url != null ? ((LoggingContextSelector) selector).getLoggerContext(contextName, url) : selector.getLoggerContext(contextName); // set the logger context for use elsewhere in the servlet context servletContext.setAttribute(Red5LoggerFactory.LOGGER_CONTEXT_ATTRIBUTE, loggerContext); // get the root logger for this context Logger logger = Red5LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME, contextName); logger.info("Starting up context: {}", contextName); } catch (Exception e) { System.err.printf("LoggingContextSelector is not the correct type: %s%n", e.getMessage()); e.printStackTrace(); } } public void contextDestroyed(ServletContextEvent event) { ServletContext servletContext = event.getServletContext(); LoggerContext context = (LoggerContext) servletContext .getAttribute(Red5LoggerFactory.LOGGER_CONTEXT_ATTRIBUTE); if (context != null) { Logger logger = context.getLogger(Logger.ROOT_LOGGER_NAME); logger.debug("Shutting down context {}", context.getName()); context.reset(); context.stop(); } else { System.err.printf("No logger context found for %s%n", event.getServletContext().getContextPath()); } } }