Working on Saturday morning :)
My code is running when JBoss is started. It's a module in my application that use this code.
Alright, so I need to mount my jar using http://community.jboss.org/wiki/VFS3UserGuide#Example_Mount_Archive_VirtualFile and then call getChildrenRecursively().
I will try these tomorrow to see which VFS's FileSsystem impl is used and test this solution.
Thank for the advise,
Guillaume.