obtaining a requestDispatcher

Question

What is the benefit of using the servletContext as opposed the request in order to obtain a requestDispatcher?

servletContext.getRequestDispatcher(dispatchPath)

and using

argRequest.getRequestDispatcher(dispatchPath)

Answer 1

It's there in the javadocs in black and white

http://java.sun.com/javaee/5/docs/api/javax/servlet/ServletRequest.html#getRequestDispatcher(java.lang.String)

The difference between this method and ServletContext.getRequestDispatcher(java.lang.String) is that this method can take a relative path.

Answer 2

When you call getRequestDispatcher from ServletContext, you need to provide an absolute path, but for ServletRequest objects, you need to provide a relative path.