request.getRequestDispatcher and getServletContext().getRequestDispatcher

The only difference is that the pathname specified in 'ServletRequest.getRequestDispatcher' does not require a leading slash, so you can use it with a relative URL. 'ServletContext.getRequestDispatcher' requires a leading slash.

Example:

RequestDispatcher dispatcher=request.getRequestDispatcher("Coreservlet");
(or)
RequestDispatcher dispatcher=request.getRequestDispatcher("/Coreservlet");


But,

RequestDispatcher
dispatcher=getServletContext().getRequestDispatcher
("/Coreservlet");