File Upload

[Martin.Trummer]

Unfortunately, I found no way of doing file uploads with RPC :-(

This is not possible due to browser security restrictions. HTML pages (java-script) are not allowed to read directly from the local file-system.
The only ways you can access the files:

• use a form as described in this thread
• include some object that is allowed to read from the file system: e.g. a java applet

[oswalsarikap]

Hello All,
I am new to this GWT world. I m trying to implement File Upload functionality and facing some errors.
Please help!

As per above discussions i tried adding the code, i have also imported the commons-fileupload.jar but getting the error as "No source code is available for type org.apache.commons.fileupload.FileUploadException; did you forget to inherit a required module?"

[oswalsarikap]

Hello All,
I am new to this extjs and gwt world. I m trying to implement File Upload functionality and facing some errors.
Please help!

As per above discussions i tried adding the code, i have also imported the commons-fileupload.jar but still getting some errors related to missing file. I have added to the classpath as well.

Error

<H1>HTTP Status 500 - </H1>
<HR noShade SIZE=1>

<P><B>type</B> Exception report</P>
<P><B>message</B> <U></U></P>
<P><B>description</B> <U>The server encountered an internal error () that prevented it from fulfilling

this request.</U></P>
<P><B>exception</B> <PRE>javax.servlet.ServletException: Servlet execution threw an exception
</PRE>
<P></P>
<P><B>root cause</B> <PRE>java.lang.NoClassDefFoundError: org/apache/commons/io/output/DeferredFileOutputStream
org.apache.commons.fileupload.disk.DiskFileItemFactory.createItem(DiskFileItemFactory.java:191)
org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:350)
org.apache.commons.fileupload.servlet.ServletFileUpload.parseRequest(ServletFileUpload.java:126)
org.gwtbook.client.MyFormHandler.getFileItem(MyFormHandler.java:47)
org.gwtbook.client.MyFormHandler.doPost(MyFormHandler.java:31)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.google.gwt.dev.shell.GWTShellServlet.service(GWTShellServlet.java:290)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
</PRE>
<P></P>
<P><B>note</B> <U>The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.</U></P>
<HR noShade SIZE=1>

<H3>Apache Tomcat/5.0.28</H3>

Do i need to add the Commons-io.jar as well ? i tried googling it but couldnt find it. Can you please guide what could be wrong while implementing.

Thanks In Advance!

[posta07]

Do i need to add the Commons-io.jar as well ? i tried googling it but couldnt find it. Can you please guide what could be wrong while implementing.

Yes, you do need commons-io also. Verify both are correctly on your build path and classpath for when you run the app.

http://commons.apache.org/io/

[posta07]

Per some requests for the File Download opposite of File Upload, I've posted some hints:

On the server side I implemented the doGet method of the HttpServlet class. I grab the raw data from the database and set it into the response (with the appropriate response type):

                BufferedOutputStream output = null;
                try {
                    RawAttachmentItem attachment = attachmentFileDao.retrieveContents(fileid);
                    ByteArrayInputStream input = new ByteArrayInputStream(attachment.getContents());
                    int contentLength = input.available();
                    
                    resp.reset();
                    resp.setContentType("application/octet-stream");
                    resp.setContentLength(contentLength);
                    resp.setHeader("Content-disposition", "attachment; filename=\"" + attachment.getFilename()
                        + "\"");
                    output = new BufferedOutputStream(resp.getOutputStream());
                    for(int data; (data=input.read()) != -1;) {
                        output.write(data);
                    }
                    output.flush();
                }
                catch (IOException e) {
                    
                    e.printStackTrace();
                }
                finally {
                    close(output);
                }

On the client side, you simple create a new iFrame with its 'src' attribute set to the servlet url for downloading the file:

        boolean frameExists = (RootPanel.get("downloadiframe") != null);
        if(frameExists) {
            Widget widgetFrame = (Widget)RootPanel.get("downloadiframe");
            widgetFrame.removeFromParent();
        }
        
        NamedFrame frame = new NamedFrame("downloadiframe");
        frame.setUrl(GWT.getModuleBaseURL() 
            + "/attachmentHandler?action=dl&fileid="
            + model.getFileId());
        frame.setVisible(false);
        
        RootPanel.get().add(frame);

When the file gets sent back to the iFrame, the browser will treat it as a file download and prompt you to do something with it (open, save, cancel, etc).

If anyone has questions or requires more detail, please do not hesitate to ask!!

[javier.garcia.parra]

After reading your work, and a couple of ... got it to work. This is what I consider more important. It's almost perfectly described in :
http://home.izforge.com/index.php/20...le-web-toolkit

Just must now:
- I added the FileUpload to a FormPanel and this to a GWTExt Panel and look very nice.
- It is required to set the name of the FileUpload widget. Otherwise you'll get crazy with a silent empty list on the servlet...

Enjoy coding!!

[qwertz]

Hi,

is it possible to combine the GWT FileUpload with other GXT FormWidgets?
I want to implement a file upload with additional metadata...

[zaccret]

File upload support is planned for 1.2 : http://www.extjs.com/products/gxt/roadmap.php

[TheBuzzer]

it is possible. like i said my project i did it already.

[amit.vankadia]

i look at your upload example which returns the uploaded file but how do i display that binary data as an Image. if i upload an image