Using Non-Javac Compilers

Contrary to this plugin's name, the Compiler Plugin does not compile the sources of your project by itself. To compile, the Compiler Plugin uses another class to compile them.

The parameter compilerId determines which class will be used.

By default, the version 4 of Maven Compiler Plugin uses the javac compiler bundled in the javax.tools package of the standard Java library. But it is possible to use any other compiler, as long the implementation declares itself as a javax.tools.JavaCompiler service. To use such an implementation:

Add the compiler implementation in the Maven compiler plugin dependencies.
Declare the compiler's identifier in the compilerId element of the Maven plugin configuration. The identifier value shall be the value returned by the JavaCompiler.name() method of the implementation.

The example below shows how to use the Eclipse compiler ecj. Note: This configuration requires Maven 4 with Maven Compiler Plugin 4.

<project>
  [...]
  <build>
    [...]
    <plugins>
      [...]
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>...</version>
        <configuration>
          <compilerId>ecj</compilerId>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.eclipse.jdt</groupId>
            <artifactId>ecj</artifactId>
            <version>...</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>

Maven 3

Version 3 of the Maven Compiler Plugin does not use the compiler directly. Instead, it uses an intermediate layer called the Plexus Compiler. The Plexus Compiler component has some compiler identifiers available under the group org.codehaus.plexus. To use any of the non-javac compilers with version 3.x of the Maven Compiler plugin, you need to declare a dependency to the Plexus artifact in your project's pom.xml. The example below shows how to use the csharp compiler:

<project>
  [...]
  <build>
    [...]
    <plugins>
      [...]
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>...</version>
        <configuration>
          <compilerId>csharp</compilerId>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.codehaus.plexus</groupId>
            <artifactId>plexus-compiler-csharp</artifactId>
            <version>...</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>