Log4j Configuration Using XML File

In this article, you will see how to generate logs using a XML file configured externally.

First create a new Java Project and configure it as Maven Project. For Reference, Click Here

Add the following dependencies in pom.xml

  <dependencies>
	  <dependency>
		<groupId>log4j</groupId>
		<artifactId>log4j</artifactId>
		<version>1.2.17</version>
	  </dependency>
  </dependencies>  

log4j.xml provides some advanced configuration options such as Filter, ErrorHandlers and few advanced Appenders.

1. XML file

The following configuration creates the same result as in previous article.

log4j.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd" >
<log4j:configuration>
 <appender name="stdout" class="org.apache.log4j.ConsoleAppender">
   <layout class="org.apache.log4j.PatternLayout">
     <param name="ConversionPattern" value="%-4r [%t] %-5p %c %x - %m%n"/>
	</layout>
     </appender>
       <root>
	  <priority value="info"></priority>
	  <appender-ref ref="stdout"/>
	</root>
</log4j:configuration>

2. Log4j in Java Program

The following Java class is a very simple example that initializes, and then uses, the Log4J logging library for Java applications.

package com.kruders;

import org.apache.log4j.Logger;

public class HelloWorld {
	static final Logger logger = Logger.getLogger(HelloWorld.class);
	
	public static void main(String[] args) {
		logger.info("Hello World!!!");
	}
}

When you run the above example you’ll get an output like:

0 [main] INFO com.kruders.HelloWorld – Hello World!!!