※単に 全部入り Jar を作るのであれば、maven-shade-plugin の方が楽なことが判明
<build>
<plugins>
・・・
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>
jar-with-dependencies
</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>attached</goal>
</goals>
</execution>
</executions>
</plugin>
・・・
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<tasks>
<zip
basedir="${basedir}"
zipfile="target/${project.build.finalName}-src.zip">
<exclude name="target/**" />
</zip>
</tasks>
</configuration>
</execution>
</executions>
</plugin>