how to reuse the definition of a number of filesets? - ant

Question

I have a number of tasks in my build.xml that all utilize the same set of filesets. E.g. something like the following (I've retain the actual names of the tasks - related to the cobertura coverage tool - but the nature of the enveloping task is immaterial to this question).
<target name="coverage-report">
<cobertura:cobertura-report destdir="${coverage.xml.dir}" format="xml">
<fileset dir="${src.dir}">
<include name="**/*.java" />
</fileset>
<fileset dir="${componentFoo.dir}/src">
<include name="**/*.java" />
</fileset>
</cobertura:cobertura-report>
</target>
<target name="summary-coverage-report">
<cobertura:cobertura-report destdir="${coverage.summaryxml.dir}" format="summaryXml">
<fileset dir="${src.dir}">
<include name="**/*.java" />
</fileset>
<fileset dir="${componentFoo.dir}/src">
<include name="**/*.java" />
</fileset>
</cobertura:cobertura-report>
</target>
<target name="alternate-coverage-report">
<cobertura:cobertura-report destdir="${coverage.html.dir}">
<fileset dir="${src.dir}">
<include name="**/*.java"/>
</fileset>
<fileset dir="${componentFoo.dir}/src">
<include name="**/*.java" />
</fileset>
</cobertura:cobertura-report>
</target>
What I would like to do is to be able to define once this recurring set of filesets and reuse it. Now, there's a related SO question on how to use the same fileset in multiple places but that's not working here as I have a number of filesets, not just one. I also tried wrapping the filesets inside a macrodef and expanding the macrodef when needed but I get the message that the these tasks "don't support the nested [name of macrodef] element". So I guess macrodefs in Ant can only be used as high-level tasks and cannot be expanded in arbitrary places.
So is there a way to reuse a definition of a number of filesets in Ant?

Answer 1

This would be easy if the cobertura tasks accepted arbitrary resource collections instead of being hard-coded to just fileset - it may be worth submitting a feature request to this end. For example with a copy task:
<resources id="filesets">
<fileset dir="${src.dir}">
<include name="**/*.java" />
</fileset>
<fileset dir="${componentFoo.dir}/src">
<include name="**/*.java" />
</fileset>
</resources>
<copy todir="dest">
<resources refid="filesets"/>
</copy>
You can fall back to the purely XML-level and use an entity reference:
<!DOCTYPE project [
<!ENTITY cobFilesets '<fileset dir="${src.dir}">
<include name="**/*.java" />
</fileset>
<fileset dir="${componentFoo.dir}/src">
<include name="**/*.java" />
</fileset>'>
]>
<project ....>
<target name="coverage-report">
<cobertura:cobertura-report destdir="${coverage.xml.dir}" format="xml">
&cobFilesets;
</cobertura:cobertura-report>
</target>
</project>