CODEWITHSUNDEEP
gwtservletsfile-upload
Filippo
Filippo

Reputation: 361

Upload image to server in GWT project using Servlet

I am developing a GWT application which, among its other functions, permits the user to upload an image file and to store it on the server. So far, that's what I've done..

SERVLET

public class ImageUploadService extends HttpServlet {

private static final int MAX_FILE_SIZE = 1 * 1024 * 1024;

public void doPost(HttpServletRequest request, HttpServletResponse response) {

    wlog("INFO: è partita la servlet");

    if (!ServletFileUpload.isMultipartContent(request))
        wlog("ERR: non è multipart!");
    ServletFileUpload fileUpld = new ServletFileUpload();

    try {
        wlog("INFO: itero file");
        FileItemIterator fileIt = fileUpld.getItemIterator(request);
        while (fileIt.hasNext()) {

            wlog("INFO: trovato file");
            FileItemStream fileStream = fileIt.next();
            BufferedInputStream in = new BufferedInputStream(
                    fileStream.openStream(), 4096);
            BufferedOutputStream out = new BufferedOutputStream(
                    new FileOutputStream("immagineSegnalazione.jpg"));

            byte[] buf = new byte[MAX_FILE_SIZE];
            int byteRead;
            while ((byteRead = in.read(buf, 0, MAX_FILE_SIZE)) >= 0) {
                out.write(buf, 0, byteRead);
            }
            in.close();
            out.flush();
            out.close();
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
}

private void wlog(String s) {
    System.out.println("UPLOAD SERVLET " + s);
}
}

MODULE ON CLIENT SIDE

            [...]

        PopupPanel inserisciSegnalazionePopup = new PopupPanel();
    final FormPanel uploadForm = new FormPanel();
    uploadForm.setEncoding(FormPanel.ENCODING_MULTIPART);
    uploadForm.setMethod(FormPanel.METHOD_POST);
    inserisciSegnalazionePopup.setAutoHideEnabled(true);
    VerticalPanel holder = new VerticalPanel();
    holder.add(new Label("se puoi, allega una foto della segnalazione"));
    final FileUpload fu = new FileUpload();
    uploadForm.add(fu);
    holder.add(uploadForm);
    uploadForm.setAction(GWT.getModuleBaseURL() + "imageUpload");
    Button inviaBtn = new Button("INVIA SEGNALAZIONE");
    inviaBtn.addClickHandler(new ClickHandler() {

        @Override
        public void onClick(ClickEvent event) {
            // TODO check file is image and size and other stuff


            uploadForm.submit();
        }

    });
    holder.add(inviaBtn);

            [...]

..plus I've rightly made the changes needed on web.xml The Servlet is correctly called and the method doPost() starts, but the FileItemIterator is always empty, as if there were no files at all.. Can someone guess what's wrong? I can't really see where's the mistake Thank you in advance

Upvotes: 1

Views: 979

Answers (3)

Filippo
Filippo

Reputation: 361

The solution is... Simply add .setName() to the FileUpload widget

Upvotes: 1

Suresh Atta
Suresh Atta

Reputation: 121998

Have you tried this ??

Iterator<FileItem> iterator = upload.parseRequest(request).iterator();

Upvotes: 1

Sarajog
Sarajog

Reputation: 164

just guessing I would say the request is parsed somewhere befor you use it. Try taking a look at that question and the answer to it, it seems to like it was nearly the same problem.

Sarajog

Upvotes: 1

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