How to Package a Mixed Java‑Groovy Maven Project in IntelliJ

Adjust project layout for mixed Java‑Groovy sources

Rename the original src/main/java directory to src/main/groovy. Maven will then treat the source tree as Groovy, allowing both Java and Groovy files to be compiled together.

POM dependencies

Add the Groovy runtime library that matches the Groovy version used in the project.

<dependency>
    <groupId>org.codehaus.groovy</groupId>
    <artifactId>groovy-all</artifactId>
    <version>2.4.8</version>
</dependency>

Build configuration

Three Maven plugins are required:

maven-compiler-plugin – compiles Java sources with Java 1.8 compatibility.

maven-jar-plugin – builds the executable JAR, adds a manifest with Class-Path and the main class.

gmaven-plugin – compiles Groovy sources, generates stubs, and integrates Groovy into the Maven lifecycle.

The complete <build> section looks like this:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.6.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
        
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.6</version>
            <configuration>
                <archive>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <classpathPrefix>lib/</classpathPrefix>
                        <mainClass>com.okayqa.studentapd.T2</mainClass>
                    </manifest>
                    <manifestEntries>
                        <Class-Path>/Users/fv/Documents/workspace/fun/build/libs/fun-1.0.jar</Class-Path>
                    </manifestEntries>
                </archive>
            </configuration>
        </plugin>
        
        <plugin>
            <groupId>org.codehaus.gmaven</groupId>
            <artifactId>gmaven-plugin</artifactId>
            <version>1.2</version>
            <configuration>
                <providerSelection>1.7</providerSelection>
            </configuration>
            <dependencies>
                <dependency>
                    <groupId>org.codehaus.gmaven.runtime</groupId>
                    <artifactId>gmaven-runtime-1.7</artifactId>
                    <version>1.2</version>
                    <exclusions>
                        <exclusion>
                            <groupId>org.codehaus.groovy</groupId>
                            <artifactId>groovy-all</artifactId>
                        </exclusion>
                    </exclusions>
                </dependency>
                <dependency>
                    <groupId>org.codehaus.groovy</groupId>
                    <artifactId>groovy-all</artifactId>
                    <version>1.7.0</version>
                </dependency>
            </dependencies>
            <executions>
                <execution>
                    <goals>
                        <goal>generateStubs</goal>
                        <goal>compile</goal>
                        <goal>generateTestStubs</goal>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Important notes

The manifestEntries block adds a local JAR to the manifest. If the path appears red in the IDE but points to an existing file, the build will still succeed.

All plugin versions shown are known to work together; adjust them only if you need newer features.

After applying the directory rename and the pom.xml changes, run mvn clean package. Maven will compile both Java and Groovy sources, generate the executable JAR, and place any dependent libraries under target/lib as specified by the manifest.