Why is my RequestDispatcher null?

[Anthony Smith]

WHy is that rd null? I printed if null then print something to the screen and sure enough it was null. Why?
public void service(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException

{
RequestDispatcher rd = getServletContext().getRequestDispatcher("mcserver_history.jsp");

HashMap hostnameMap = populateObject();
request.setAttribute("hostnameMap",hostnameMap);
rd.forward(request,response);
}

[William Brogden]

It seems likely that that string creates an invalid URL as far as the servlet context is concerned.
Bill

[Anthony Smith]

It is not the URL, that is the problem.

[Michael Fitzmaurice]

Hi Anthony
The following is lifted from the API docs for ServletContext.getRequestDispatcher():

Returns a RequestDispatcher object that acts as a wrapper for the resource located at the given path. A RequestDispatcher object can be used to forward a request to the resource or to include the resource in a response. The resource can be dynamic or static.
The pathname must begin with a "/" and is interpreted as relative to the current context root. Use getContext to obtain a RequestDispatcher for resources in foreign contexts. This method returns null if the ServletContext cannot return a RequestDispatcher.

Your pathname does not begin with a "/" character - have you tried changing this?
[ October 24, 2003: Message edited by: Michael Fitzmaurice ]
[ October 24, 2003: Message edited by: Michael Fitzmaurice ]

[Mike Curwen]

If you don't like that, you should try the

request.getRequestDispatcher() method, where the API indicates a more forgiving attitude:

The pathname specified may be relative, although it cannot extend outside the current servlet context. If the path begins with a "/" it is interpreted as relative to the current context root.