One of the great things about Maven is that it does so much for you. Unfortunately, this also means that it must make a lot of assumptions (and a few restrictions) in order to do this well. One example is that of creating redistributables. Commons::Net is used mainly for FTP (probably about 90%+ of its users just use this functionality). Thus, I wanted to create a smaller FTP-client only jar alongside the main package. Unfortunately, I couldnt find a way to get Maven to do this. I guess I could have written a Mojo-based plugin that would allow me to specify and generate separate redistributables, but this seemed like a lot of work just for this task. The basic limitation comes from the module-centric way that Maven looks at projects and redistributable package, and in this case, I wasn’t satisfied that I could split the project up in a way that would suit both me and Maven’s requirements. Thankfully, there is an easier way: just use the Maven AntRun plugin:
<plugin>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<configuration>
<tasks>
<jar destfile="target/commons-net-ftp-${version}.jar">
<fileset dir="target/classes"
includes="org/apache/commons/net/ftp/**,
org/apache/commons/net/*,
org/apache/commons/net/io/*,org/apache/commons/net/util/*"/>
<fileset dir="${basedir}" includes="LICENSE.txt"/>
<manifest>
<attribute name="Implementation-Vendor" value="Apache Software Foundation"/>
</manifest>
</jar>
</tasks>
</configuration>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
</plugin>
As you can see from the section marked in bold, you have access to the properties exposed by the POM. You just need to hook the task into a specific phase in the lifecycle (I have hooked it into the “package” phase). Of course, if your task is not going to be trivial, you can always encapsulate it in a separate build file and invoke it using Ant’s ant taskdef.