Assuming that groovy codes are in src/main/groovy and java codes are in src/main/java.
We can use 2 maven-compiler-plugin to compile groovy and java, and add groovy-all dependency. And finally we can find the both groovy and java class files in jar.
<plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.2</version> <configuration> <source>${java.version}</source> <target>${java.version}</target> <encoding>${project.build.sourceEncoding}</encoding> </configuration> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.2</version> <configuration> <compilerId>groovy-eclipse-compiler</compilerId> </configuration> <dependencies> <dependency> <groupId>org.codehaus.groovy</groupId> <artifactId>groovy-eclipse-compiler</artifactId> <version>2.9.2-01</version> </dependency> <dependency> <groupId>org.codehaus.groovy</groupId> <artifactId>groovy-eclipse-batch</artifactId> <version>2.4.3-01</version> </dependency> </dependencies> </plugin>
<dependency> <groupId>org.codehaus.groovy</groupId> <artifactId>groovy-all</artifactId> <version>2.4.3</version> </dependency>