Problem using Commons fileupload for progress bar with Javaworld example

From:

lielar <lielar@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 24 Aug 2008 21:32:54 -0700 (PDT)

Message-ID:

<7bc4a237-3da1-43d2-b1e7-b33ce56591c2@r15g2000prh.googlegroups.com>

Hi

I'm using Apache Commons for FileUpload to do a progress bar using
Ajax. I'm using prototype for ajax. I'm having trouble trying to track
the progress of the file upload. I'm using the example at http://www.javaworld.com
/javaforums/showthreaded.php?Cat=2&Number=49773&page=0.

Here is the relevant code ...
<snip>

            FileItemFactory factory = new DiskFileItemFactory();
            ServletFileUpload upload = new ServletFileUpload(factory);
            CustomProgressListener l = new CustomProgressListener();
            upload.setProgressListener(l);
            fileID = Integer.parseInt(generateRandomNumber(4));
            l.setId(fileID);
            map2.put(fileID, l);
            try {
                List<FileItem> items = upload.parseRequest(req);
                System.out.println("UploadMe::process2 items "+items);
                for (Iterator<FileItem> i = items.iterator(); i.hasNext(); ) {
                    FileItem item = i.next();
                    System.out.println("FileUpload::process2 name "+item.getName());
                    item.write(new File(PATH+item.getName()));
                }

                res.setContentType("text/html");
                System.out.println("UploadMe::process2 after parseRequest");
                PrintWriter pw = res.getWriter();
                pw.write("\n\t<html><head><title></title></head><body>");
                pw.write("<script type=\"text/javascript
\">window.parent.queryMyProgress('"+fileID+"')</script>");
                pw.write("</body></html>");
                pw.flush();
            } catch (Exception e) {
                e.printStackTrace();
            }
</snip>

I found that when the code hits 'upload.parseRequest', the servlet
completes that line, that is uploads the file before proceeding. Hence
I can't track the file upload even using the ProgressListener
implementation.

The map, is just keeping track of the instance so that I can load the
object again. In the Javaworld example, they use the session.

Has anybody come across issues? How can I make sure that parseRequest
is executed, but the servlet doesn't complete the step?

Everything else (ie, AJAX communicating) works.

Cheers
Patrick