Log4j is a logging mechanism that is in Apache foundation project. Log4j is for Java project. Here, to add logging feature to your Java project, you can use one as following ways:

Manually

  1. Visit http://logging.apache.org/log4j/
  2. Download the Log4j jar library
  3. Manually include it into your project dependency
  4. All manage by yourself, you need to do everything

If there is Log4j version upgrade, you need to repeat above steps again.

Maven 2 – Recommended

Use Maven 2 or 3 to handle the build for you. See how to install it in previous post.

You can just add into your pom.xml as following:

<dependencies>
<!-- other dependencies -->
        <dependency>
			<groupId>log4j</groupId>
			<artifactId>log4j</artifactId>
			<version>1.2.15</version>
	    </dependency>
<!-- other dependencies -->
</dependencies>

So with maven, when you want to change version, you just need to update the version tag as above (Ex: 1.2.15)