How can I create an executable JAR with dependencies using Maven

Question

I want to package my project in a single executable JAR for distribution.

How can I make a Maven project package all dependency JARs into my output JAR?

Answer 1

Hello @kartik,

You can use the dependency-plugin to generate all dependencies in a separate directory before the package phase and then include that in the classpath of the manifest:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <executions>
        <execution>
            <id>copy-dependencies</id>
            <phase>prepare-package</phase>
            <goals>
                <goal>copy-dependencies</goal>
            </goals>
            <configuration>
                <outputDirectory>${project.build.directory}/lib</outputDirectory>
                <overWriteReleases>false</overWriteReleases>
                <overWriteSnapshots>false</overWriteSnapshots>
                <overWriteIfNewer>true</overWriteIfNewer>
            </configuration>
        </execution>
    </executions>
</plugin>
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <configuration>
        <archive>
            <manifest>
                <addClasspath>true</addClasspath>
                <classpathPrefix>lib/</classpathPrefix>
                <mainClass>theMainClass</mainClass>
            </manifest>
        </archive>
    </configuration>
</plugin>

Alternatively use ${project.build.directory}/classes/lib as OutputDirectory to integrate all jar-files into the main jar, but then you will need to add custom classloading code to load the jars.