Portlets can delegate the execution of logic or creation of content to servlets and JSPs.
This is useful for implementing the Model-View-Controller pattern where the portlet may
act as controller and dispatch to different JSPs for rendering the views.
The PortletRequestDispatcher interface provides a mechanism to accomplish this
Servlets and JSPs invoked from within a portlet in the render phase should generate
markup fragments following the recommendations of the PLT.B Markup Fragment
You have the choose to use the include or forward methode.