Maven: Assemble Child Project (module) In Multi Module Project

Question

The following setup:

rootpom
 |- parentpom
 |   |- projectApom
 |   |- projectBpom
 |   |- other projects poms
 |- other projects poms

Each project in the hierarchy is bound by using <module> tag on its parent pom as well the parent being specified by the <parent> tag.

ProjectA and ProjectB both specify the assembly plugin using the fragment:

<plugin>
  <artifactId>maven-assembly-plugin</artifactId>
  <version>2.6</version>
  <configuration>
    <archive>
      <manifest>
        <mainClass>ClassToExecute</mainClass>
      </manifest>
    </archive>
    <descriptorRefs>
      <descriptorRef>jar-with-dependencies</descriptorRef>
    </descriptorRefs>
  </configuration>
</plugin>

Now I go to the directory of the rootpom and execute:

mvn --projects parent/projectB compile assembly:single

The problem is now that projectB depends on A (and some others) so using this command assembly:single will be applied to all the projects.

So the question goes how can I compile multiple projects (dependencies) and only assemble a single one (the last)?

Answer 1

Simple: don't use assembly:single on the command line but bind an execution of the maven-assembly-plugin to a particular phase for the project you want.

If you only want to assemble only project B then in B's POM, you would have:

<plugin>
  <artifactId>maven-assembly-plugin</artifactId>
  <version>2.6</version>
  <executions>
    <execution>
      <phase>package</phase>
      <goals>
        <goal>single</goal>
      </goals>
      <configuration>
        <archive>
          <manifest>
            <mainClass>ClassToExecute</mainClass>
          </manifest>
        </archive>
        <descriptorRefs>
          <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
      </configuration>
    </execution>
  </executions>
</plugin>

This way, running mvn --projects parent/projectB clean package will package only B.