If the servlet calls the bean's method(s), directly or indirectly, then the
bean should not call the servlet's.  The servlet should retrieve the result of
the bean method and do all the forwarding itself.

Having the bean do servlet things is very bad design.  It's especially bad
having it do navigation things.  Do not have the bean do servlet things.

public class Controller extends HttpServlet
{
 protected void doPost( HttpServletRequest request,
                        HttpServletResponse response )
     throws ServletException, IOException
 {
   Map parms = request.getParameterMap();
   Result res = doSomething( parms );

   request.setAttribute( "result", res );

   RequestDispatcher rd;
   switch( res.getStatus() )
   {
    case SUCCESS:
      rd = request.getRequestDispatcher( "/success.jsp" );
      break;

    default:
    case FAILURE:
      rd = request.getRequestDispatcher( "/failure.jsp" );
      break;
   }
   rd.forward( request, response );
 }
}