Ant script: Prevent duplication of JAR in javac-classpath war-lib - ant

Question

I have a ANT script and I have a lot of duplicated path to same set JAR files.
But there is so many double wording in the classpath and also in the war element.
<path id="my.classpath">
<pathelement location="folderA/subFolderA/1.0/A.jar"/>
<pathelement location="folderC/subFolderB/1.0/B.jar"/>
<pathelement location="folderF/subFolderZ/2.0/Z.jar"/>
<pathelement location="compile/subFolderX/1.0/onlyForJavac.jar"/>
</path>
....
<javac ...>
<classpath refid="my.classpath" />
</javac>
....
<war ...>
<lib file="folderA/subFolderA/1.0/A.jar"/>
<lib file="folderC/subFolderB/1.0/B.jar"/>
<lib file="folderF/subFolderZ/2.0/Z.jar"/>
<lib file="moreFolderF/subFolderZ/2.0/additionFile.jar"/>
<lib file="moreFolderF/subFolderZ/2.0/additionRuntimeFile.jar"/>
</war>
I want to summary them into ONE list which is easier to keep update.
But I am blocked as I have no idea how to share a path-like-structure with a fileset-like-structure.

Answer 1

Since Ant 1.8.0 there is a new resource collection - mappedresources that
can be used in place of the war task lib element.
So, the task might look like this (pretty much straight from the docs):
<war ... >
<mappedresources>
<restrict>
<path refid="my.classpath"/>
<type type="file"/>
</restrict>
<chainedmapper>
<flattenmapper/>
<globmapper from="*" to="WEB-INF/lib/*"/>
</chainedmapper>
</mappedresources>
</war>
This feature was added to resolve a long-standing feature request to make
the task flatten jars when deploying to WEB-INF/lib.
previous answer:
Although you can't easily convert a path to a fileset with vanilla Ant, you can go the other way.
So one option would be to define your jars in a fileset, and derive the path from it.
Something like this perhaps:
<fileset id="my.fileset" dir="${basedir}">
<include name="folderA/subFolderA/1.0/A.jar"/>
<include name="folderC/subFolderB/1.0/B.jar"/>
<include name="folderF/subFolderZ/2.0/Z.jar"/>
<include name="moreFolderF/subFolderZ/2.0/additionFile.jar"/>
<include name="moreFolderF/subFolderZ/2.0/additionRuntimeFile.jar"/>
</fileset>
<path id="my.classpath">
<fileset refid="my.fileset" />
</path>
<!-- javac stays the same -->
<war ...>
<lib refid="my.fileset" />
</war>
Another possibility is to use the ant-contrib pathtofileset task.

Answer 2

Another solution, possibly 'not the best' will be to place required jar file in WEB-INF/lib, and then set the classpath from there.
<path id="compile.classpath">
<fileset dir="${lib.dir}" includes="*.jar"/>
</path>
When its time to build the war, you need not worry about the <lib> at all, as jars are already placed in WEB-INF/lib folder.
<war destfile="${dist.dir}/${project.name}.war" webxml="${web.dir}/WEB-INF/web.xml">
<fileset dir="${web.dir}"/>
<classes dir="${build.dir}/classes"/>
</war>