File Upload

[Joel Trunick]

How do I use the DropPanel to upload files? I'd like to be able to
drag/drop files and have them uploaded.

[walid dahhane]

code GWT: 

@Override
            public void onDrop(final DropEvent event) {
                event.stopPropagation();
                event.preventDefault();

                final RequestBuilder rb = new
RequestBuilder(RequestBuilder.POST, "./servletUpload");

                final String
type=event.getDataTransfer().getFiles().getItem(0).getType();
                final String
name=event.getDataTransfer().getFiles().getItem(0).getName();

                final FileReader fileReader=new FileReader();
                LoadHandler handler=new LoadHandler() {

                    @Override
                    public void onLoad(LoadEvent evt) {

                        rb.setHeader("filename", name);
                        rb.setHeader("Content-Type", type
+";charset=ISO-8859-1");

                        try {

                            rb.sendRequest(fileReader.getResult(),
                                new RequestCallback() {

                                    @Override
                                    public void onError(Request arg0,
Throwable arg1) {
                                    }

                                    @Override
                                    public void
onResponseReceived(Request arg0,
                                            Response arg1) {
                                        rb.setHeader("Content-Type",
type+";charset=ISO-8859-1");

                                    } }
                            );
                        } catch (RequestException e1) {
                            // TODO Auto-generated catch block
                            e1.printStackTrace();
                        }

                    }
                };;;

fileReader.readAsBinaryString(event.getDataTransfer().getFiles().getItem(0));

                fileReader.addLoadHandler(handler);

            }
        });

Code Java:

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

                File f = new File(request.getHeader("filename"));

                Base64InputStream decodingStream = new
Base64InputStream(request.getInputStream());

                Writer w = new BufferedWriter(new OutputStreamWriter(new
FileOutputStream(f),Charset.forName("ISO-8859-1")));

                int c;
                while((c=decodingStream.read())!=-1){
                        w.write(c);
                }
                w.flush();
                w.close();
                decodingStream.close();

}

[jgh...@gmail.com]

Using your code, I've only managed to save text files, I don't save other formats, for example pdf

Could save other formats?

[Lukas Laag]

Yes, you can save other formats than text. It depends on the method
you invoke on FileReader: readAsText(), readAsArrayBuffer(),
readAsBinaryString. It also depends on which browser / platform you
are using. Support for the File API is not available everywhere. What
browser / os are you using ?

Lukas

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[jgh...@gmail.com]

thanks for the reply

I am using mozilla Version 15.0.1 and Chromme 25.0.1364.152m

Only text files saved, the rest is created with the correct name and format but the wrong content

The code I am using is as follows:

@UiHandler("dropPanel")

public void onDrop(final DropEvent event) {

    event.stopPropagation();

    event.preventDefault();

    final RequestBuilder rb = new RequestBuilder(RequestBuilder.POST, "myURL");

    final String type = event.getDataTransfer().<DataTransferExt>cast().getFiles().getItem(0).getType();

    final String name = event.getDataTransfer().<DataTransferExt>cast().getFiles().getItem(0).getName();

    final FileReader fileReader = new FileReader();

    LoadHandler handler = new LoadHandler() {

        @Override

        public void onLoad(LoadEvent evt) {

            rb.setHeader("filename", name);

            rb.setHeader("Content-Type", type + ";charset=ISO-8859-1");

            try {

                rb.sendRequest(fileReader.getStringResult(), new RequestCallback() {

                    @Override

                    public void onError(Request arg0, Throwable arg1) {

                    }

                    @Override

                    public void onResponseReceived(Request arg0, Response arg1) {

                        rb.setHeader("Content-Type", type + ";charset=ISO-8859-1");

                        }

                    }

                );

            } catch (RequestException e1) {

                // TODO Auto-generated catch block

                 e1.printStackTrace();

            }

        }

    };

    fileReader.readAsBinaryString(event.getDataTransfer().<DataTransferExt>cast().getFiles().getItem(0));

    fileReader.addLoadHandler(handler);

}

And on the server:

@Override

public void doPost(HttpServletRequest request, HttpServletResponse

        response) throws ServletException, IOException {

    File f = new File("C:\\myUrlLocal", request.getHeader("filename"));

    Writer w = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(f)));

    int c;

    while ((c = request.getInputStream().read()) != -1) {

        w.write(c);

    }

    w.flush();

    w.close();

    request.getInputStream().close();

}

thank you very much

[Lukas Laag]

Hi,
I do not think the problem is related to the file API. I think it is
related to the transfer part and the choice of encoding. I am not very
experienced in this area, but I think that if the file you are trying
to send is a binary file, you cannot send it as ISO-8859-1, which is a
text encoding for latin alphabets. You need to find a code sample
which uses RequestBuilder to upload binary files and see how they do
it.

Lukas