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Servlets and RequestDispatcher.include()

Posted on 2001-09-13
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Last Modified: 2013-11-24
Hi,

I am having a problem with the RequestDispatcher and the include() method.

Whenever I execute the include() method, the response gets comitted immediatly after finishing processing of the include. I have tried increasing the buffer size dramatically.  This prevents me from using the forward() method

I have just installed JRun 3.1 and this code now throws the following exception....(although it worked perfectly in Jrun 3.0 Sp2a.)

java.lang.IllegalStateException: Response has already been committed
        at allaire.jrun.servlet.JRunResponse.resetContent(../servlet/JRunResponse.java:172)
        at allaire.jrun.servlet.JRunSE.runServlet(../servlet/JRunSE.java:1201)
        at allaire.jrun.servlet.JRunRequestDispatcher.forward(../servlet/JRunRequestDispatcher.java:89)
        at com.concept.mercedes.servlet.DispatcherServlet.service(DispatcherServlet.java:102)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at allaire.jrun.servlet.JRunSE.service(../servlet/JRunSE.java:1416)
        at allaire.jrun.session.JRunSessionService.service(../session/JRunSessionService.java:1082)
        at allaire.jrun.servlet.JRunSE.runServlet(../servlet/JRunSE.java:1270)
        at allaire.jrun.servlet.JRunNamedDispatcher.forward(../servlet/JRunNamedDispatcher.java:39)
        at allaire.jrun.servlet.Invoker.service(../servlet/Invoker.java:84)
        at allaire.jrun.servlet.JRunSE.service(../servlet/JRunSE.java:1416)
        at allaire.jrun.session.JRunSessionService.service(../session/JRunSessionService.java:1082)
        at allaire.jrun.servlet.JRunSE.runServlet(../servlet/JRunSE.java:1270)
        at allaire.jrun.servlet.JRunRequestDispatcher.forward(../servlet/JRunRequestDispatcher.java:89)
        at allaire.jrun.servlet.JRunSE.service(../servlet/JRunSE.java:1552)
        at allaire.jrun.servlet.JRunSE.service(../servlet/JRunSE.java:1542)
        at allaire.jrun.servlet.JvmContext.dispatch(../servlet/JvmContext.java:364)
        at allaire.jrun.jrpp.ProxyEndpoint.run(../jrpp/ProxyEndpoint.java:388)
        at allaire.jrun.ThreadPool.run(../ThreadPool.java:272)
        at allaire.jrun.WorkerThread.run(../WorkerThread.java:75)

Through debugging I have narrowed it down to the commented lines in the souce below (look for NOTE...)

  public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    System.err.println("Executing DispatcherServlet...");

    response.setContentType("text/plain");

    String[] controllers = request.getParameterValues("controller");
    String view = request.getParameter("view");
    String originatingPageView = request.getParameter("originatingPageView");
    RequestDispatcher rd = null;

    try {
      // process all the controllers
      for (int i = 0; i < controllers.length; i ++) {

        rd = getServletContext().getRequestDispatcher(controllers[i]);

        if (rd == null) {
          System.err.println("DispatcherServlet error - No controller named : " + controllers[i]);
        } else {
          // invoke the controller
          System.err.println("Invoking : " + controllers[i]);
          // NOTE : response not commited here
          rd.include(request, response);
          // NOTE : response commited here
        }
      }

      // forward to the appropriate view appending any querystring info that might have been added to the request object
      QueryString qString = (QueryString)request.getAttribute("queryString");
      if (qString != null) {
        view = view + qString.toString();
      }

      rd = getServletContext().getRequestDispatcher(view);

      if (rd == null) {
        System.err.println("DispatcherServlet error - No view named : " + view);
      } else {
        System.err.println("Forwarding without errors : " + view);
        // NOTE : Fails here as already comitted.
        rd.forward(request, response);
      }

    } catch (ServletException e) {

      System.err.println("Root Cause --------------- : " + e.getRootCause());
      QueryString qString = (QueryString)request.getAttribute("queryString");
      // don't allow null values for qString object.
      if (qString == null) qString = new QueryString();

      if (e.getRootCause() instanceof InvalidParameterException) {

        // String redirect = originatingPageView;
        rd = getServletContext().getRequestDispatcher(originatingPageView + qString);

      } else if (e.getRootCause() instanceof SessionTimedOutException) {

        rd = getServletContext().getRequestDispatcher(loginView + qString);
      } else {

        rd = getServletContext().getRequestDispatcher(errorView + qString);
      }

      if (rd == null) {
        System.err.println("DispatcherServlet error - No errorView named : " + originatingPageView);
      } else {
        request.setAttribute("exception", e.getMessage());
        System.err.println("Forwarding with errors : " + errorView);
        rd.forward(request, response);
      }
    }
  }

If anyone has any insight, that would be great.
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Question by:robinM
2 Comments
 

Author Comment

by:robinM
ID: 6480883
I have just had a break through, deep in the depths of the allaire knowledge base is the following article which points to a hotfix.

                     http://www.allaire.com/Handlers/index.cfm?ID=21853&Method=Full

                     JRun Hot Fixes Build 16777

                     Fixes the following bug that was causing me errors...

                     26529 - 3.1 Regression. Servlet using getRequestDispatcher with an unbounded array of URLs causes "response has been closed" in Jrun 3.1. ex: RequestDispatcher dispatcher =
                     req.getRequestDispatcher(urlstrings);

                     After the install, all was good again....
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Lunchy earned 0 total points
ID: 6480906
Adding to PAQ Database
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