log4j Getting started with log4j Installation and Setup


Example

Installation

Installation of Log4j2 is as simple as putting log4j2 jar in application classpath. Though you might want to customize logs output through additional config file

Configuration

maven

To add log4j to project in maven, add it's dependency: In pom.xml add following dependency:

<dependencies>
  <dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-api</artifactId>
    <version>${log4j2.version}</version>
  </dependency>
  <dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>${log4j2.version}</version>
  </dependency>
</dependencies>

springboot with maven

Spring-boot is commonly used framework for web application. It features support auto-configuration for many features including logging façade like log4j2. To add log4j2 to your spring-boot project make sure you exclude default logging façade: commons-logging. Log4j will be used, when it is only logging façade on classpath.

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
        <!-- exclude spring-boot java commons logging in favour of log4j2 -->
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <!-- add log4j2 to spring-boot: -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j2</artifactId>
    </dependency>

Notice, that there is no version in above snippet. It is because project inherit version from parent. Make sure you also inherit from spring-boot-starter-parent, by adding:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.3.3.RELEASE</version>
</parent>

ivy

In ivy.xml, add following dependency:

<dependencies>
  <dependency org="org.apache.logging.log4j" name="log4j-api" rev="${log4j2.version}" />
  <dependency org="org.apache.logging.log4j" name="log4j-core" rev="${log4j2.version}" />
</dependencies>

gradle

In your .gradle file:

dependencies {
  compile group: 'org.apache.logging.log4j', name: 'log4j-api', version: '2.6.2'
  compile group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.6.2'
}