JSR 168 portlets use the PortletRequestDispatcher to delegate responsibility to servlets and JSPs. The PortletRequestDispatcher can only be used while the portlet is processing a render action. Th e request dispatcher is obtained from the portlet context by using either the getRequestDispatcher or the getNamedDispatcher method.
The getRequestDispatcher method takes a String representing the context root relative path of the included file. This path must begin with a ‘/’. This method will return null if the path is not found.
While using the getRequestDispatcher method, you may include parameters in the path. For example, if your path is /mypath/myjsp.jsp, you can include parameters ...