Maven Shade Plugin to produce two Jars

Question

Till now I was using maven assembly plugin to generate two JARs for each artifact - compiled sources and dependencies - the reason for this was simple - deploying only the compiled sources over network is significantly faster than deploying all-in-one-JAR with 40 MB of data.

Because of overwriting of inner files I had to switch for maven shade plugin to be able to use the <transformers> feature. However I am unable to manage to run both of the two executions:

<plugins>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <executions>
      <execution>
        <id>shade-libs</id>
        <phase>package</phase>
        <goals>
          <goal>shade</goal>
        </goals>
        <configuration>
          <outputFile>target/assembly/${project.artifactId}-libs.jar</outputFile>
          <artifactSet>
            <excludes>
              <exclude>...</exclude>
            </excludes>
          </artifactSet>
          <transformers>
            <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
              <resource>META-INF/spring.handlers</resource>
            </transformer>
            <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
              <resource>META-INF/spring.schemas</resource>
            </transformer>
          </transformers>
        </configuration>
      </execution>
    </executions>
  </plugin>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <executions>
      <execution>
        <id>shade-main</id>
        <phase>package</phase>
        <goals>
          <goal>shade</goal>
        </goals>
        <configuration>
          <outputFile>target/assembly/${project.artifactId}.jar</outputFile>
          <artifactSet>
            <includes>
              <include>...</include>
            </includes>
          </artifactSet>
        </configuration>
      </execution>
    </executions>
  </plugin>
</plugins>

When I run mvn package, only the second execution is run. The first one is always ignored. With maven assembly plugin it worked perfectly.

Of course the solution could be to use both assembly and shade plugin at the same time, but I would like to find more consistent solution.

Answer 1

Instead of defining the plugin twice, simply define it once but with two execution sections. So in your situation it would be:

<plugins>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <executions>
      <execution>
        <id>shade-libs</id>
        <phase>package</phase>
        <goals>
          <goal>shade</goal>
        </goals>
        <configuration>
          <outputFile>target/assembly/${project.artifactId}-libs.jar</outputFile>
          <artifactSet>
            <excludes>
              <exclude>...</exclude>
            </excludes>
          </artifactSet>
          <transformers>
            <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
              <resource>META-INF/spring.handlers</resource>
            </transformer>
            <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
              <resource>META-INF/spring.schemas</resource>
            </transformer>
          </transformers>
        </configuration>
      </execution>
      <execution>
        <id>shade-main</id>
        <phase>package</phase>
        <goals>
          <goal>shade</goal>
        </goals>
        <configuration>
          <outputFile>target/assembly/${project.artifactId}.jar</outputFile>
          <artifactSet>
            <includes>
              <include>...</include>
            </includes>
          </artifactSet>
        </configuration>
      </execution>
    </executions>
  </plugin>
</plugins>