You must be wondering what went wrong with MVC. When application gets large you cannot stick to bare bone MVC. You have to extend it somehow to deal with these complexities. One mechanism of extending MVC that has found widespread adoption is based on a configurable controller Servlet. The MVC with configurable controller servlet.
When the HTTP request arrives from the client, the Controller Servlet looks up in a properties file to decide on the right Handler class for the HTTP request.This Handler class is referred to as the Request Handler. The Request Handler contains the presentation logic for that HTTP request including business logic invocation. In other words, the Request Handler does everything that is needed to handle the HTTP request. The only difference so far from the bare bone MVC is that the controller servlet looks up in a properties file to instantiate the Handler instead of calling it directly.
