LoggerContextFilter.java

/*
 * RED5 Open Source Flash Server - http://code.google.com/p/red5/
 * 
 * Copyright 2006-2012 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.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.slf4j.LoggerFactory;

import ch.qos.logback.classic.LoggerContext;

/**
 * A servlet filter that puts this contexts LoggerContext into a Threadlocal variable.
 * 
 * It removes it after the request is processed.
 *
 * To use it, add the following lines to a web.xml file
 *<pre>
	<filter>
		<filter-name>LoggerContextFilter</filter-name>
		<filter-class>org.red5.logging.LoggerContextFilter</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>LoggerContextFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
 *</pre>
 *
 * @author Paul Gregoire (mondain@gmail.com)
 */
public class LoggerContextFilter implements Filter {

	private String contextName;

	public void destroy() {
	}

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		//System.out.printf("Context name: %s\n", contextName);
		LoggingContextSelector selector = (LoggingContextSelector) Red5LoggerFactory.getContextSelector();
		//System.out.printf("Context select type: %s\n", selector.getClass().getName());
		LoggerContext ctx = selector.getLoggerContext(contextName);
		//load default logger context if its null
		if (ctx == null) {
			//System.out.println("Logger context was null, getting default");
			ctx = (LoggerContext) LoggerFactory.getILoggerFactory();
		}
		//evaluate context name against logger context name
		if (!contextName.equals(ctx.getName())) {
			System.err.printf("Logger context name and context name dont match (%s != %s)\n", contextName, ctx.getName());
		}
		//System.out.printf("Logger context name: %s\n", ctx.getName());
		selector.setLocalContext(ctx);
		try {
			chain.doFilter(request, response);
		} finally {
			selector.removeLocalContext();
		}
	}

	public void init(FilterConfig config) throws ServletException {
		contextName = config.getServletContext().getContextPath().replaceAll("/", "");
	}
}