building ant task jar (needs commons-net in ant classpath!!) if you want support for extracting tar archives (recommended), you need to set anttarsupport=true (default) in the build properties and the Java Activation Framework in the ant classpath taskdef name="if" classname="util.ant.If" classpath="${build.outdir}/${jarname}_ant.jar"/ taskdef name="true" classname="util.ant.True" classpath="${build.outdir}/${jarname}_ant.jar"/ taskdef name="false" classname="util.ant.False" classpath="${build.outdir}/${jarname}_ant.jar"/ taskdef name="false" classname="util.ant.Install" classpath="${build.outdir}/${jarname}_ant.jar"/ taskdef name="false" classname="util.ant.FileFinder" classpath="${build.outdir}/${jarname}_ant.jar"/