Using maven-dependency-plugin to copy shaded artifact

Question

I have a Maven project Foo, which uses maven-shade-plugin to package a webstart fat jar, one that includes all its dependencies.

<plugin>
    <artifactId>maven-shade-plugin</artifactId>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <finalName>foo-fat</finalName>
                ...

Another project is Bar, which is a web application that, among other things, distributes the Foo webstart. I need to copy foo-fat.jar into the Bar interim pre-package directory and for that, I am using maven-dependency-plugin:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <executions>
        <execution>
            <id>copy</id>
            <phase>prepare-package</phase>
            <goals>
                <goal>copy</goal>
            </goals>
            <configuration>
                <artifactItems>
                    <artifactItem>
                        <groupId>my-group</groupId>
                        <artifactId>foo</artifactId>
                        <outputDirectory>...</outputDirectory>                  
                    </artifactItem>
                </artifactItems>
            </configuration>
        </execution>
    </executions>
</plugin>

The problem is, this doesn't fetch foo-fat.jar but has Foo generate a simple jar foo.jar that doesn't include dependencies. It may be relevant to note that the only artifact Foo has in the local repo is the slim jar and I was unable to get the fat jar there by running any Maven lifecycle. Running mvn clean package in Foo directly does package a fat jar but not when called from Bar's pom.xml as is shown above.

How do I get maven-dependency-plugin to use a different project artifact, such as the fat jar made by the shade plugin?

Answer 1

For Foo class to be able to generate a fat jar when using maven install or maven package you will need to use maven-shade-plugin, which you are already doing but the key step there is to make sure to use a shadedClassifierName in its configuration. For example:

<artifactId>maven-shade-plugin</artifactId>
  <executions>
    <execution>
      <phase>package</phase>
      <goals>
        <goal>shade</goal>
      </goals>
      <configuration>
        <shadedClassifierName>shaded</shadedClassifierName>
        <shadedArtifactAttached>true</shadedArtifactAttached>
      </configuration>
    </execution>
  </executions>

Then in the Bar class in order to include the fat jar of Foo class you will need to use maven-dependency-plugin with copy goal and there make sure to annotate the artifactItem with shaded classifier

For Example:

<plugin>
  <artifactId>maven-dependency-plugin</artifactId>
    <executions>
      <execution>
        <goals>
          <goal>copy</goal>
        </goals>
        <configuration>           
          <outputDirectory>${project.build.directory}/temp</outputDirectory>
          <artifactItems>
            <artifactItem>
              <groupId>...</groupId>
              <artifactId>...</artifactId>
              <version>${project.version}</version>
              <type>jar</type>
              <classifier>shaded</classifier>
            </artifactItem>
          </artifactItems>
        </configuration> 
      </execution>
    </executions>
</plugin>

Answer 2

Re: "this [Bar][...] has Foo generate a simple jar foo.jar" – Are you sure that this is not from a previous build of Foo? Since dependency:copy just:

... copies a list of artifacts from the repository to defined locations

and re: "when [Foo] called from Bar's pom.xml as is shown above" – You can't "call", i.e. run a build of, a project from another one (but from an aggregator/multi-module project or with the Maven Invoker Plugin or a Groovy or Ant script or the like).

---

Now the idea for an answer (without having tried it):

Use install:install-file in Foo's install phase to make your foo-fat.jar a "real" artifact in your local repo and use this in Bar's <artifactItem> declaration.