Question

I am trying to add groovy to an existing Java Maven project that leverages Lombok. Unfortunately when I enable the groovy-maven-eclipse compiler with the pom fragment below, my lombok annotated java files fail to compile. As far as I can tell, Lombok is not participating in the compilation of java files at all.

<plugin>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>2.3.1</version>
    <configuration>
        <compilerId>groovy-eclipse-compiler</compilerId>
        <verbose>true</verbose>
    </configuration>
    <dependencies>
        <dependency>
            <groupId>org.codehaus.groovy</groupId>
            <artifactId>groovy-eclipse-compiler</artifactId>
            <version>2.6.0-01-SNAPSHOT</version>
        </dependency>
    </dependencies>
</plugin>

I should also point out that while in eclipse (with m2e) everything works fine. My problem arises when I try to do a mvn package.

Answer 1

@Todd: The groovy-eclipse-compiler is the best choice if you don’t need to developp maven plugin with some groovy tooling (see http://groovy.codehaus.org/Groovy-Eclipse+compiler+plugin+for+Maven).

@Ambience: you reached the issue related at http://jira.codehaus.org/browse/GRECLIPSE-1293.
This bug is now fixed with latest groovy-eclipse-compiler 2.6.1-01-SNAPSHOT.

Note: The latest version available is now 2.9.1-01, see http://docs.groovy-lang.org/latest/html/documentation/tools-groovyeclipse.html

You have to modify your pom like this:

<plugin>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.1</version>
    <configuration>
      <compilerId>groovy-eclipse-compiler</compilerId>
      <verbose>true</verbose>   
      <fork>true</fork> 
      <compilerArguments>
        <javaAgentClass>lombok.launch.Agent</javaAgentClass>
      </compilerArguments>
    </configuration>
    <dependencies>
        <dependency>
            <groupId>org.codehaus.groovy</groupId>
            <artifactId>groovy-eclipse-compiler</artifactId>
            <version>2.9.1-01</version>
        </dependency>
        <!-- for 2.8.0-01 and later you must have an explicit dependency on groovy-eclipse-batch -->
        <dependency>
            <groupId>org.codehaus.groovy</groupId>
            <artifactId>groovy-eclipse-batch</artifactId>
            <version>2.3.7-01</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.4</version>
        </dependency>
    </dependencies>
</plugin>

The mandatory parts:

<fork>true</fork>

<compilerArguments>
    <javaAgentClass>lombok.launch.Agent</javaAgentClass>
</compilerArguments>

The added dependency on lombok inside the maven-compiler-plugin

Edit: update versions