Spring Framework example source code file (Log4jNestedDiagnosticContextFilter.java)

This example Spring Framework source code file (Log4jNestedDiagnosticContextFilter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

abstractrequestloggingfilter, abstractrequestloggingfilter, http, log4jnesteddiagnosticcontextfilter, log4jnesteddiagnosticcontextfilter, logger, logger, request, response, servlet, string, string

The Spring Framework Log4jNestedDiagnosticContextFilter.java source code

/*
 * Copyright 2002-2005 the original author or authors.
 *
 * 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.springframework.web.filter;

import javax.servlet.http.HttpServletRequest;

import org.apache.log4j.Logger;
import org.apache.log4j.NDC;

/**
 * Request logging filter that adds the request log message to the Log4J
 * nested diagnostic context (NDC) before the request is processed,
 * removing it again after the request is processed.
 *
 * @author Rob Harrop
 * @author Juergen Hoeller
 * @since 1.2.5
 * @see #setIncludeQueryString
 * @see #setBeforeMessagePrefix
 * @see #setBeforeMessageSuffix
 * @see #setAfterMessagePrefix
 * @see #setAfterMessageSuffix
 * @see org.apache.log4j.NDC#push(String)
 * @see org.apache.log4j.NDC#pop()
 */
public class Log4jNestedDiagnosticContextFilter extends AbstractRequestLoggingFilter {

	/** Logger available to subclasses */
	protected final Logger log4jLogger = Logger.getLogger(getClass());


	/**
	 * Logs the before-request message through Log4J and
	 * adds a message the Log4J NDC before the request is processed.
	 */
	protected void beforeRequest(HttpServletRequest request, String message) {
		if (log4jLogger.isDebugEnabled()) {
			log4jLogger.debug(message);
		}
		NDC.push(getNestedDiagnosticContextMessage(request));
	}

	/**
	 * Determine the message to be pushed onto the Log4J nested diagnostic context.
	 * <p>Default is a plain request log message without prefix or suffix.
	 * @param request current HTTP request
	 * @return the message to be pushed onto the Log4J NDC
	 * @see #createMessage
	 */
	protected String getNestedDiagnosticContextMessage(HttpServletRequest request) {
		return createMessage(request, "", "");
	}

	/**
	 * Removes the log message from the Log4J NDC after the request is processed
	 * and logs the after-request message through Log4J.
	 */
	protected void afterRequest(HttpServletRequest request, String message) {
		NDC.pop();
		if (log4jLogger.isDebugEnabled()) {
			log4jLogger.debug(message);
		}
	}

}