Apache Maven is a powerful build automation tool used primarily for Java projects. One of the essential aspects of Maven is its plugin system, which extends its functionality. Among these plugins, the Maven Compiler Plugin is crucial as it compiles the source code of a Maven project. This blog post will provide an in-depth look at the Maven Compiler Plugin, including how to use it with the latest version.
The Maven Compiler Plugin is used to compile Java source files. It leverages the javac compiler to convert .java files into .class files, which can be executed by the Java Virtual Machine (JVM). By configuring this plugin, you can specify the JDK version, additional compiler options, and even perform annotation processing.
Latest Version
To use the Maven Compiler Plugin, you need to configure it in your project's pom.xml file. Here is a step-by-step guide on how to do it.
Step 1: Basic Configuration
First, open your pom.xml file and add the following configuration inside the <build> section:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.10.1</version>
<configuration>
<source>21</source>
<target>21</target>
</configuration>
</plugin>
</plugins>
</build>
Explanation
Step 2: Additional Configuration Options
The Maven Compiler Plugin provides several additional configuration options. Here are some common ones:
Specify Encoding
<configuration>
<encoding>UTF-8 </encoding>
</configuration>
Enable Debug Information
<configuration>
<debug>true </debug>
</configuration>
Compiler Arguments
<configuration>
<compilerArgs>
<arg>-Xlint:unchecked</arg>
<arg>-Xlint:deprecation</arg>
</compilerArgs>
</configuration>
Let's create a simple Java project to demonstrate the Maven Compiler Plugin.
Step 1: Create a Maven Project
Run the following command to create a new Maven project:
mvn archetype:generate -DgroupId=com.example -DartifactId=compiler-plugin-demo -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false
Step 2: Update pom.xml
Navigate to the project directory and open the pom.xml file. Add the Maven Compiler Plugin configuration as shown earlier:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>compiler-plugin-demo</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>21</maven.compiler.source>
<maven.compiler.target>21</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.10.1</version>
<configuration>
<source>21</source>
<target>21</target>
<encoding>UTF-8</encoding>
<compilerArgs>
<arg>-Xlint:unchecked</arg>
<arg>-Xlint:deprecation</arg>
</compilerArgs>
</configuration>
</plugin>
</plugins>
</build>
</project>
Step 3: Create a Simple Java Class
Navigate to the src/main/java/com/example directory and create a file named App.java with the following content:package com.example;
/**
* Hello world!
*
*/
public class App
{
public static void main( String[] args )
{
System.out.println( "Hello World!" );
}
}
Step 4: Compile and Run the Project
Use the following Maven commands to compile and run your project:
mvn clean install
mvn exec:java -Dexec.mainClass="com.example.App"
You should see the following output:
Hello World!
The Maven Compiler Plugin is power tool for any Java developer using Maven. By configuring this plugin, you can control the Java version, encoding, and compiler options, ensuring that your project is built correctly. Always remember to use the latest version of the plugin to take advantage of new features and improvements. This guide should help you get started with the Maven Compiler Plugin and configure it according to your project's needs.