Guide:
http://docs.codehaus.org/display/GROOVY/Groovy-Eclipse+compiler+plugin+for+Maven
Sample:
http://stackoverflow.com/questions/3251016/getting-groovy-maven-and-eclipse-to-play-nice-together
Note: Groovy-Eclipse VS Gmaven, they are diff
Guide:
http://docs.codehaus.org/display/GROOVY/Groovy-Eclipse+compiler+plugin+for+Maven
Sample:
http://stackoverflow.com/questions/3251016/getting-groovy-maven-and-eclipse-to-play-nice-together
Note: Groovy-Eclipse VS Gmaven, they are diff