Integrating the RemoteServiceServlet with existing J2EE application servlet

I ran into a road block using GWT 2.0 integrated with existing J2EE Servlet Applciation. I currently have a J2EE Servlet application which the mainServlet implements all kinds of security protection from cross site scripting, session management/timeout, and configuration loading. So, I need to

Integrating the RemoteServiceServlet with existing J2EE application servlet

I ran into a road block using GWT 2.0 integrated with existing J2EE Servlet Applciation. I currently have a J2EE Servlet application which the mainServlet implements all kinds of security protection from cross site scripting, session management/timeout, and configuration loading. So, I need to