Display a tree(directory tree) on a web page

First I apologize but I was not sure on which forum this should be posted.
I have currently a jar file which helps me display on a web page the structure and displays the files in a text format. As I don’t have the source of it I tried to decompile it make some cosmetic changes and then compile it again. Well it doesn’t work even if I don’t make any changes so my assumption is that the decompiler is missing something which is not added to the jar when recompiled. I don’t encounter any errors but it just doesn’t do the job for me. I would appreciate if anyone has any knowledge of any tool/script which can do this for me. It will have to be a jar file as I don’t have admin rights on the linux boxes to do any settings.
Thank you for your replies.