We'd prefer that you keep the conversation here.
I think in that case you're out of luck. Have you looked at just getting a better app server?
you change a JSP, Jasper regenerates the servlet code, the servlet gets compiled, and then gets loaded
The main servlet would delegate all of its work to other classes that it loaded itself through its own ClassLoader. When it needed to reload the classes, it could simply create a new ClassLoader and do so.
Are you sure you are not making things unecessarily complicated?
I would consider writing the code in a scripting language
returning the results as an XML document rather than a serialized object