Question

How can I build a separate jar for a specific package in a project?
I have a project structure like this:

Project Something
  |
  |-> DifferentPackages

Or a jar for each package using a build.xml?

Answer 1

In your build xml, define one task each to produce one jar. With in the task, use fileset to include only specific package.

Once done, create a wrapper task and make it dependent on all the jars tasks created above or wrap all jar creation tasks in the new task itself. Make this a default target.

e.g.

<project name="project" default="AllJars" basedir=".">
  <target name="AllJars" depends="compile">
   <mkdir dir="dist"/>
   <jar jarfile="dist/jar1.jar">
     <fileset dir="build">
         <include name="package1/*.class"/>
     </fileset>
    </jar>
    <jar jarfile="dist/jar2.jar">
     <fileset dir="build">
         <include name="package2/*.class"/>
     </fileset>
    </jar>
  </target>
 </project>