How to save an EMF model to a hierarchy of folders and files
===

I am implementing a commercial RCP application where the user can create projects for example of this format:

Project1
 SubElement1
 SubElement2
   SubSubElement1
Project2
....

etc.

I am using EMF to model the data domain and I want to save the data.I want to have a hierarchy
of folders and files for each project e.g.
Folder 1 should be Project1 containing a Folder SubElement1 which contains some xml files. etc.

I found examples to save EMF models but I didn't figure out how to save this folder-files hierarchy under one EMF resource...