How can I create an executable JAR with dependencies using Maven?
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>
</build>
and you run it with
mvn clean compile assembly:single
Compile goal should be added before assembly:single or otherwise the code on your own project is not included.
See more details in comments.
Commonly this goal is tied to a build phase to execute automatically. This ensures the JAR is built when executing mvn install
or performing a deployment/release.
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id> <!-- this is used for inheritance merges -->
<phase>package</phase> <!-- bind to the packaging phase -->
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
Taking IAdapter's answer and reformatting it, we have:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>
</build>
Next, I would recommend making this a natural part of your build, rather than something to call explicitly. To make this a integral part of your build, add this plugin to your pom.xml
and bind it to the package
lifecycle event. However, a gotcha is that you need to call the assembly:single
goal if putting this in your pom.xml, while you would call 'assembly:assembly' if executing it manually from the command line.
<project>
[...]
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-my-jar-with-dependencies</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
[...]
</plugins>
[...]
</build>
</project>
See executable-jar-with-maven-example (GitHub)
Notes
Those pros and cons are provided by Stephan.
For Manual Deployment
- Pros
- Cons
- Dependencies are out of the final jar.
Copy Dependencies to a specific directory
<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>${project.build.directory}/${project.build.finalName}.lib</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
Make the JAR File Executable and Classpath Aware
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>${project.build.finalName}.lib/</classpathPrefix>
<mainClass>${fully.qualified.main.class}</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
At this point the JAR file is actually executable with external classpath elements.
java -jar target/${project.build.finalName}.jar
Make Deployable Archives
The JAR file is only executable with the sibling ...lib/
directory. We need to make archives to deploy with the directory and its content.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<id>antrun-archive</id>
<phase>package</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<target>
<property name="final.name" value="${project.build.directory}/${project.build.finalName}"/>
<property name="archive.includes" value="${project.build.finalName}.${project.packaging} ${project.build.finalName}.lib/*"/>
<property name="tar.destfile" value="${final.name}.tar"/>
<zip basedir="${project.build.directory}" destfile="${final.name}.zip" includes="${archive.includes}" />
<tar basedir="${project.build.directory}" destfile="${tar.destfile}" includes="${archive.includes}" />
<gzip src="${tar.destfile}" destfile="${tar.destfile}.gz" />
<bzip2 src="${tar.destfile}" destfile="${tar.destfile}.bz2" />
</target>
</configuration>
</execution>
</executions>
</plugin>
Now you have target/${project.build.finalName}.(zip|tar|tar.bz2|tar.gz)
which each contains the jar
and lib/*
.
Apache Maven Assembly Plugin
- Pros
- Cons
- No class relocation support (use maven-shade-plugin if class relocation is needed).
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<archive>
<manifest>
<mainClass>${fully.qualified.main.class}</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</execution>
</executions>
</plugin>
You have target/${project.bulid.finalName}-jar-with-dependencies.jar
.
Apache Maven Shade Plugin
- Pros
- Cons
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<shadedArtifactAttached>true</shadedArtifactAttached>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>${fully.qualified.main.class}</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
You have target/${project.build.finalName}-shaded.jar
.
onejar-maven-plugin
- Pros
- Cons
- Not actively supported since 2012.
<plugin>
<!--groupId>org.dstovall</groupId--> <!-- not available on the central -->
<groupId>com.jolira</groupId>
<artifactId>onejar-maven-plugin</artifactId>
<executions>
<execution>
<configuration>
<mainClass>${fully.qualified.main.class}</mainClass>
<attachToBuild>true</attachToBuild>
<!-- https://code.google.com/p/onejar-maven-plugin/issues/detail?id=8 -->
<!-- classifier>onejar</classifier -->
<filename>${project.build.finalName}-onejar.${project.packaging}</filename>
</configuration>
<goals>
<goal>one-jar</goal>
</goals>
</execution>
</executions>
</plugin>
Spring Boot Maven Plugin
- Pros
- Cons
- Add potential unnecessary Spring and Spring Boot related classes.
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
<configuration>
<classifier>spring-boot</classifier>
<mainClass>${fully.qualified.main.class}</mainClass>
</configuration>
</execution>
</executions>
</plugin>
You have target/${project.bulid.finalName}-spring-boot.jar
.
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 file, but then you will need to add custom classloading code to load the JAR files.