I want to reload just my web layer classes without reloading my service layer classes (which take longer to initialize and change less frequently). There are no references from my service layer into the web layer and I can create a whole new instance of the web layer without problems.

I can conceive of a solution involving complicated class-loader tricks to isolate the web layer in its own class-loader and I think this is probably the only way to do this so what I'm asking is, is there a library out there which does this?

I know about JavaRebel - I don't need that much power and I'm really looking for a more lightweight free solution.