Page Comparison

With the upload component, you can access the local file system of the client to select any files and upload them on the server.

Variant 1: Property "Immediate = false" 

The component consists of two buttons: the first opens the local file manager and enables the selection of a file, whereas the second starts the upload activity.
The name of the selected file will be displayed between the two buttons. Important: The upload does not start until the "Upload" button is pressed.

Variant 2: Property "Immediate = true" 

The component consists of only one button. This triggers the filechooser and the upload immediately. Important: The upload is triggered immediately after the file selection.

Image Added

The upload component requires a "receiver" which receives the file on the server side and processes it. The receiver can be initialized in the constructor or in the INIT-event of the respective window. See code example below.

Important properties:

• ButtonCaption - Label of the upload button.

• Include Page
  Property Caption Property Caption

• Receiver - The receiver is an object that processes the file on the server side.

• Include Page
  Property TabIndex Property TabIndex

Important events:

• uploadFailed - Is triggered when the upload fails.
• uploadFinished - Is triggered as soon as the upload has ended. At this point, it is still not clear if the upload was successful.
• updateProgress - Is triggered regularly during the upload. Thus it is possible to track the progress of the upload.
• uploadStarted - Is triggered as soon as the upload has started.
• uploadSucceeded - Is triggered as soon as the upload has ended and was successful.

...

// For later usage, e.g. in a message displayed by uploadSucceeded-Event
File file;


// Build receiverpublic class MainView extends XdevView {

	File file;

	/**
	 *
	 */
	public MainView() {
		super();
		this.initUI();

		final Receiver receiver = new Receiver() {

		    @Override
		    public OutputStream receiveUpload(final String filename, final String mimeType) {
		        // Create upload stream to write to

		        FileOutputStream fos = null;
		        try {

		            	// Get path to servlet's temp directory
		            	final File temporaryDirectory = (File) VaadinServlet.getCurrent().getServletContext().getAttribute(ServletContext.TEMPDIR);

		            // Concatenate temporaryDirectory with filename and open the file for writing.
		            MainView.this.file = new File(temporaryDirectory, filename);

		            	// Create the output stream
		            fos = new FileOutputStream(MainView.this.file);

		        } catch (final java.io.FileNotFoundException e) {
		            Notification.show("Could not open file", Type.ERROR_MESSAGE);
		            return null;
		        }
		        return fos;
		    }
		};
		
		// Set Receiver for upload component
		this.upload.setReceiver(receiver);


	}