Spring MVC + Log4j Integration Example

In this tutorial, we will show you how to integrate the log4j framework with the Spring MVC web application.

All you need to do is :

1. Include the log4j.jar as the project dependency.
2. Create a log4j.properties file and put it into the root of the classpath (for Maven, put it into the resources folder).

Technologies and tools used :

1. Log4j 1.2.17
2. Spring 4.0.5.RELEASE
3. Maven 3
4. Tomcat 6
5. Eclipse Kepler 4.3

Note
By default, Spring is using the JCL dependency (commons-logging), and it has a runtime discovery algorithm to find out for other logging frameworks in well known places on the project classpath.

1. Project Directory

Review the final project structure.

2. Project Dependencies

Declares the following dependencies :

pom.xml

	
<properties>
		<spring.version>4.0.5.RELEASE</spring.version>
		<log4j.version>1.2.17</log4j.version>
		<jstl.version>1.2</jstl.version>
	</properties>
 
	<dependencies>
 
		<!-- Spring framework -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-core</artifactId>
			<version>${spring.version}</version>
		</dependency>
 
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>${spring.version}</version>
		</dependency>
 
		<!-- Log4j -->
		<dependency>
			<groupId>log4j</groupId>
			<artifactId>log4j</artifactId>
			<version>${log4j.version}</version>
		</dependency>
 
		<!-- jstl , for JSP, optional -->
		<dependency>
			<groupId>jstl</groupId>
			<artifactId>jstl</artifactId>
			<version>${jstl.version}</version>
		</dependency>
 
	</dependencies>

3. log4j.properties

Create a log4j properties file, and put it into the resources folder, refer to step #1.

log4j.properties

# Root logger option
log4j.rootLogger=DEBUG, stdout, file
 
# Redirect log messages to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
 
# Redirect log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
#outputs to Tomcat home
log4j.appender.file.File=${catalina.home}/logs/myapp.log
log4j.appender.file.MaxFileSize=5MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

4. Spring MVC Controller + Message Logging

A simple controller to return a welcome page. Furthermore, it shows you how to use log4j to do the message logging.

WelcomeController.java

package com.mkyong.common.controller;
 
import org.apache.log4j.Logger;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
 
@Controller
public class WelcomeController {
 
	private static final Logger logger = Logger.getLogger(WelcomeController.class);
 
	@RequestMapping(value = "/", method = RequestMethod.GET)
	public ModelAndView getWelcome() {
 
		//logs debug message
		if(logger.isDebugEnabled()){
			logger.debug("getWelcome is executed!");
		}
 
		//logs exception
		logger.error("This is Error message", new Exception("Testing"));
 
		ModelAndView model = new ModelAndView("welcome");
		model.addObject("msg", "Hello Spring MVC + Log4j");
		return model;
 
	}
 
}

5. Demo

Run the web application, and access the welcome controller.

5.1 All logging messages will be displayed in the console.

log4j.properties

# Redirect log messages to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

Eclipse console

Jul 03, 2014 7:19:31 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/11  config=null
Jul 03, 2014 7:19:31 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 1162 ms
2014-07-03 19:19:43 ERROR WelcomeController:23 - This is Error message
java.lang.Exception: Testing
	at com.mkyong.common.controller.WelcomeController.getWelcome(WelcomeController.java:23)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)

5.2 Furthermore, a logging file is created in the Tomcat’s logs folder.

log4j.properties

log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=${catalina.home}/logs/myapp.log
log4j.appender.file.MaxFileSize=5MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

D:\apache-tomcat-6.0.37\logs\myapp.log

Jul 03, 2014 7:19:31 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/11  config=null
Jul 03, 2014 7:19:31 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 1162 ms
2014-07-03 19:19:43 ERROR WelcomeController:23 - This is Error message
java.lang.Exception: Testing
	at com.mkyong.common.controller.WelcomeController.getWelcome(WelcomeController.java:23)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)

Download Source Code

Download it –  Log4j-SpringMVC-Example.zip (11 KB)

References

1. Spring Reference – Using log4j
2. log4j 1.2 official page
3. log4j hello world example
4. log4j.properties examples

转：http://www.mkyong.com/spring-mvc/spring-mvc-log4j-integration-example/