On Mon, Jul 12, 2010 at 7:26 PM, Jeff Chimene <[email protected]> wrote:
> On 07/11/2010 11:17 AM, Roope wrote:
> > Hi
> >
> > I'm currently developing some bioinformatics tools and I want to make
> > them as web apps.
> >
> > The thing is that user needs to input files that might be up to 4Gb
> > but usually the biggest is just about 250Mb.
> >
> > There are two main use-cases:
> > 1. Steaming the file and taking just some small parts of it to string
> > 2. Reading the whole file and making object from each line in file
> >
> > I would like to do all the file processing in client side, but I
> > understood that it is not yet possible using gwt?
>
> In general the answer is yes, but not because of GWT. Until wide-spread
> browser support of HTML 5 which will provide better local file handling.
So GWT wont support it yet and there might be some browsers that do support
it. So I could use those browser that do support it and use
some JavaScript code?
> > If I keep the server local it is feasible to upload some 250mb files
> > and process them at the server side, but I have no success so far in
> > this, even with 10mb file.
>
> You might provide some background on the "... no success so far..." path.
>
I managed to upload some over 1MB files but the over 10MB didn't upload.
Here is the server side code, copied most of it and the rest of the code I
show from some example how to do this or from forums.
import org.apache.commons.fileupload.FileItemIterator;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class FileUpload extends HttpServlet {
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
try {
ServletFileUpload upload = new ServletFileUpload();
res.setContentType("text/plain");
FileItemIterator iterator = upload.getItemIterator(req);
while (iterator.hasNext()) {
copy(iterator.next().openStream(), res.getOutputStream());
}
} catch (Exception ex) {
throw new ServletException(ex);
}
}
public static void copy(InputStream is, OutputStream os) throws IOException
{
byte buffer[] = new byte[8192];
int bytesRead;
BufferedInputStream bis = new BufferedInputStream(is);
while ((bytesRead = bis.read(buffer)) != -1) {
os.write(buffer, 0, bytesRead);
}
is.close();
os.flush();
os.close();
}
}
Here is the the part from web.xml needed(replace * with your own stuff)
<servlet>
<servlet-name>fileUploaderServler</servlet-name>
<servlet-class>com.*.*.server.FileUpload</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>fileUploaderServler</servlet-name>
<url-pattern>/*/fileupload</url-pattern>
</servlet-mapping>
...and here is the code for the form that uses the fileupload
private static FormPanel getForm(final DialogBox dialogBox,final TextArea
ta) {
final FormPanel form = new FormPanel();
form.setAction(GWT.getModuleBaseURL() + "fileupload");
// Because we're going to add a FileUpload widget, we'll need to set the
// form to use the POST method, and multipart MIME encoding.
form.setEncoding(FormPanel.ENCODING_MULTIPART);
form.setMethod(FormPanel.METHOD_POST);
// Create a panel to hold all of the form widgets.
final VerticalPanel panel = new VerticalPanel();
form.setWidget(panel);
// Create a FileUpload widget.
final FileUpload upload = new FileUpload();
upload.setName("uploadFormElement");
panel.add(upload);
HorizontalPanel horizontal = new HorizontalPanel();
// Add a 'submit' button.
horizontal.add(new Button("Submit", new ClickHandler() {
public void onClick(ClickEvent event) {
form.submit();
}
}));
// Add a 'cancel' button.
horizontal.add(new Button("Cancel", new ClickHandler() {
public void onClick(ClickEvent event) {
dialogBox.hide();
}
}));
panel.add(horizontal);
// Lets add handlers
form.addSubmitHandler(new SubmitHandler() {
@Override
public void onSubmit(SubmitEvent event) {
if (upload.getFilename().length() == 0) {
Window.alert("Must select a valid file");
event.cancel();
}
}
});
form.addSubmitCompleteHandler(new SubmitCompleteHandler() {
public void onSubmitComplete(SubmitCompleteEvent event) {
ta.setText(event.getResults());
dialogBox.hide();
}
});
return form;
}
>
> For files of this size, I'd consider creating a file share on the server
> or using FTP. I'm guessing the data collection occurs on the PC? If so,
> you won't be able to process the files locally until HTML 5 and local
> file support. Depending on your environment, you might be able to
> remote-mount a disk device and write directly to that device from the
> data collection source.
> So what would you suggest me to do? Besides dumping the web
> > application idea and making some java applet.
>
> You want to move the data to the server, construct a server app that
> retrieves data slices on demand and sends them to the client for
> rendering. You can certainly do the Java app on the server to
> retrieve/preprocess the data, then render it on the client using various
> graphing packages. Search this list for pointers to SVG, or graphing
> libraries.
I will probably make java applet that can do the parsing of the file for the
user and the the result, the smaller files, will be uploaded to server and
then the string or required objects from that file are returned. This way it
is done at the "cleint side" but without including the web application in
the process. After GWT and the browsers update to support reading file at
client side I will dump the java tool.
Is there way to check how big the file is that the user is trying to send?
Besides at the server side..
Thank you for the help!
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