public class Relay extends HttpServlet {   
    @Override
    public void service(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        String command = request.getParameter("command");
        RequestDispatcher rd =request.getRequestDispatcher(command);
        rd.forward(request, response);
        System.out.println("Request forwarded to " + command + " servlet");
    }
}

Este es mi relé servelt, estoy enviando fecha desde

 <form action="Relay" method="POST" enctype="multipart/form-data"> /
 <input  type="hidden" name="command" value="AddProduct" />
<input type="text" name="pname" value="" />
<input name="" type="submit" value="Add Product">
</form>

Se está dando una java.lang.NullPointerException. enctype = "multipart / form-data" // cuando elimino funciona bien