Groovy-Eclipse provides a compiler plugin for Maven. Using the compiler plugin, it is possible to compile your maven projects using the Groovy-Eclipse compiler.
The most recent version of the Groovy-Eclipse-Compiler plugin for maven is 2.9.1-01. The most recent version of the groovy-eclipse-batch artifact is 2.3.7-01. They are both available from maven central.
In the plugin section, change the compiler used by the
Like the javac ant task,
the maven-compiler-plugin does not actually compile, but rather
delegates the compilation to a different artifact (in our case, the
<build> ... <plugins> <plugin> <artifactId>maven-compiler-plugin</artifactId> <!-- 2.8.0-01 and later require maven-compiler-plugin 3.1 or higher --> <version>3.1</version> <configuration> <compilerId>groovy-eclipse-compiler</compilerId> </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> </dependencies> </plugin> </plugins> ... </build>
This will allow Groovy files to be compiled. The groovy-eclipse-compiler recognizes all settings supported by the maven-compiler-plugin.
Remember that you still need to specify a groovy artifact as a build
dependency in addition to the
maven-compiler-plugin dependency. The
groovy dependency version should match the compiler version. Something
<dependencies> ... <dependency> <groupId>org.codehaus.groovy</groupId> <artifactId>groovy-all</artifactId> <version>2.3.7</version> </dependency> ... </dependencies>
Note that the groovy-eclipse-compiler and groovy-eclipse-batch artifacts are available in Maven-central, so there is no need to explicitly declare any extra repositories.
There are several ways to set up your maven project to recognize Groovy source files
The simplest way to set up your source folders is to do nothing at all:
add all of your Groovy files to
This requires absolutely no extra configuration and is easy to
implement. However, this is not a standard maven approach to setting up
your project. If you require a more standard maven approach, then it is
possible to put your Groovy files in
src/test/groovy and you Java files in
src/test/java. There are several ways of doing this.
If there is at least one file (Java or not) in
all files in
src/main/groovy will be found. If, however,
src/main/java is empty, then
src/main/groovy will be ignored. You
can get around this by placing an empty file in
src/main/java just so
src/main/groovy will be recognized. The same is true for
(You only need this approach if your project has an empty
If your project has no Java files and you don’t want to add an empty
src/main/java, then you can configure source files by
referencing the groovy-eclipse-compiler mojo. Just add this to the
plugins section of your pom:
<build> ... <plugin> <groupId>org.codehaus.groovy</groupId> <artifactId>groovy-eclipse-compiler</artifactId> <version>2.9.1-01</version> <extensions>true</extensions> </plugin> ... </build>
<extensions>true</extensions> section is important because this
redefines the default lifecycle of your project so that an extra phase
is added. This phase has an extra goal attached to it that adds the two
Groovy source folders.
(You only need this approach if your project has an empty
build-helper-maven-plugin allows you to do things like adding
extra source folders to your project without needing to redefine the
default lifecycle. You need to add this configuration to your build
<build> ... <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>build-helper-maven-plugin</artifactId> <version>1.5</version> <executions> <execution> <id>add-source</id> <phase>generate-sources</phase> <goals> <goal>add-source</goal> </goals> <configuration> <sources> <source>src/main/groovy</source> </sources> </configuration> </execution> <execution> <id>add-test-source</id> <phase>generate-test-sources</phase> <goals> <goal>add-test-source</goal> </goals> <configuration> <sources> <source>src/test/groovy</source> </sources> </configuration> </execution> </executions> </plugin> ... </build>
The benefit of using this approach is that you do not need to make any changes to the default lifecycle. The downside is, of course, that you need 31 lines of configuration to do this!
The source code for the plugin itself is available from the github repository.
GMaven 1.x had limitations over the groovy-eclipse-compiler and for the following reasons GMaven 2.0 compilation is no longer supported:
The compiler plugin does not require the creation of Java stubs so that your Groovy files can compile against Java files. This will prevent some arcane compile errors from appearing.
The Groovy-Eclipse compiler is the same inside Eclipse and inside Maven, and so configuration across the two platforms can be simplified.
The compiler plugin is a standard compiler plugin for Maven. It therefore follows all allows all the same standard configuration that the Javac compiler plugin uses. This makes it simpler to introduce Groovy into an existing Maven project. All you need to do is change the compiler plugin that the pom references.
There are still some reasons to use GMaven:
GroovyDoc tool is not supported because the compiler plugin does not produce stubs.
Groovy Mojos are not supported.
Groovy scripts cannot be executed in your poms.
Whether or not the Groovy-Eclipse compiler plugin for Maven is appropriate for your project will depend on your requirements.
Project Lombok is compatible with the groovy-eclipse-compiler. There is some extra configuration that you need to do. The lombok jar needs to be added to both the build and compile dependencies sections:
<dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.14.8</version> </dependency>
Also, the following configuration needs to be added to the maven-compiler-plugin configuration:
<configuration> <compilerId>groovy-eclipse-compiler</compilerId> <verbose>true</verbose> <compilerArguments> <javaAgentClass>lombok.core.Agent</javaAgentClass> </compilerArguments> <fork>true</fork> </configuration>
If you are going to be working with your maven project inside of Eclipse, it is strongly recommended that you use m2eclipse. And to use your Groovy projects with m2eclipse, you will need to install the Groovy-Eclipse configurator for m2eclipse. This feature is available any of the Groovy-Eclipse update sites (e.g., nightly, milestone, or release). Just go to your Eclipse update manager and add the Groovy-Eclipse update sites (if you haven’t done so already). Select the Groovy-Eclipse M2E integration.
The Groovy-Eclipse configurator for m2eclipse is not compatible with AspectJ or Scala. So you cannot use a joint AspectJ/Scala/Groovy project in Eclipse. These languages must be separated into separate sub-projects.