Include jar-with-dependencies in separate assembly?

Question

I'm using the maven assembly plugin to package a distributable ZIP archive. However, I would like to include the result of a separate assembly, jar-with-dependencies, inside my final archive. How can I do this? I realize that I could probably just include the JAR manually, but how can I ensure that my custom assembly will run after the JAR assembly?

Answer 1

You can use a multimodule project for that:

parent
  |- ...
  |- jar-with-dependencies-module
  |- final-zip-module

In the jar-with-dependencies module, you assemble the "uber-jar" with all dependencies. The build configuration in the POM should look something like this:

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-assembly-plugin</artifactId>
      <version>2.3</version>
      <configuration>
        <descriptorRefs>
          <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
      </configuration>
      <executions>
        <execution>
          <phase>package</phase>
          <goals>
            <goal>single</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

In the final-zip-module you can add the jar-with-dependencies as a dependency and use it in the assembly descriptor for the ZIP file. The POM would look something like this:

<project>
  ...

  <dependencies>
    <dependency>
      <groupId>com.example</groupId>
      <artifactId>jar-with-dependencies-module</artifactId>
      <version>1.0.0-SNAPSHOT</version>
      <classifier>jar-with-dependencies</classifier>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-assembly-plugin</artifactId>
        <version>2.3</version>
        <configuration>
          <appendAssemblyId>false</appendAssemblyId>
          <descriptors>
            <descriptor>src/main/assembly/assembly.xml</descriptor>
          </descriptors>
        </configuration>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>single</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

And the assembly descriptor would look something like this:

<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd">

  <id>final-assembly</id>
  <formats>
    <format>zip</format>
  </formats>

  <dependencySets>
    <!-- Include the jar-with-dependencies -->
    <dependencySet>
      <includes>
        <include>com.example:jar-with-dependencies-module:*:jar-with-dependencies</include>
      </includes>
      <useProjectArtifact>false</useProjectArtifact>
      <!-- Don't use transitive dependencies since they are already included in the jar -->
      <useTransitiveDependencies>false</useTransitiveDependencies>
    </dependencySet>t>
  </dependencySets>
</assembly>

Because of the dependency to jar-with-dependency-module, maven will build the final-zip-module always after your uber-jar was built.