JProgressBar and file transfer

Question

Hi, I am trying to use a JProgressBar to determine how many bytes have been sent so far. I have constructed the JProgressBar with the maximum size of the file size. For each 'segment' of the file sent, the progress bar should increment using the setProgress() within the SwingWorker class. If I print the values out, they appear to be correct. However, if I use setProgress() the file transfer seems to fail (not even begin).
Here's the relevant code:
public class FileTracker extends JDialog implements PropertyChangeListener {
     private JPanel mainPnl = new JPanel(new BorderLayout());
     private JPanel progressBarPnl = new JPanel(new BorderLayout());
     private JPanel midPnl = new JPanel(new GridBagLayout());
     private JPanel bottomPnl = new JPanel(new GridBagLayout());
     private JLabel fileNameLbl = new JLabel("File name: ");
     private JLabel fileNamexLbl = new JLabel();
     private JLabel sizeLbl = new JLabel("File size: ");
     private JLabel sizexLbl = new JLabel();
     private JButton cancelBtn = new JButton("Cancel");
     private JProgressBar progressBar;
     private FileSender fileSender;
     private FileReceiver fileReceiver;
     private File file;
     public FileTracker(JFrame parent, String ip, int port, File file) {
          super (parent);
          this.file = file;
          fileSender = new FileSender(ip, port, file);
          fileSender.addPropertyChangeListener(this);
          fileSender.execute();
          setLocationRelativeTo(null);
          progressBar = new JProgressBar();
          progressBar.setMaximum((int)file.length());
          add(progressBarPanel());
          setResizable(false);
          setTitle("File sending..");
          pack();
          setVisible(true);
     private JPanel progressBarPanel() {
          progressBar.setValue(0);
          progressBar.setEnabled(true);
          progressBar.setStringPainted(true);
          progressBar.setIndeterminate(true);
          progressBarPnl.add(progressBar, BorderLayout.CENTER);
          return progressBarPnl;
     public void propertyChange(PropertyChangeEvent evt) {
        if ("progress" == evt.getPropertyName()) {
            int progress = (Integer) evt.getNewValue();
            if (progressBar.isIndeterminate())
                 progressBar.setIndeterminate(false);
            progressBar.setValue(progress);
            if (fileSender != null && fileSender.isDone())
                 progressBar.setString("Transfer finished");
            if (fileReceiver != null && fileReceiver.isDone())
                 progressBar.setString("Transfer finished");
}The SwingWorker:
public class FileSender extends SwingWorker<Void, Void> {
     private Socket socket;
     private FileInputStream fileIn;
     private OutputStream output;
     private File file;
     private byte buffer[];
     private int bufferSize;
     int bytesRead;
     int progress = 0;
     public FileSender(String ipAddress, int port, File file) {
          try {
               System.out.printf("NOTICE: FileSender initialised. Sending to:%s on port: %d\n", ipAddress, port);
               socket = new Socket(InetAddress.getByName(ipAddress), port);
               output = socket.getOutputStream();
               bufferSize = socket.getSendBufferSize();
               buffer = new byte[bufferSize];
               this.file = file;
               setProgress(0);
          } catch (UnknownHostException e) {
               // THE USER MUST BE INFORMED THAT THE RECIPIENT COULD NOT BE RESOLVED
               e.printStackTrace();
          } catch (java.net.ConnectException ce) {
               // INFORM THE USER THAT THE RECIPIENT COULD NOT BE REACHED
               ce.printStackTrace();
          } catch (IOException e) {
               e.printStackTrace();
     public Void doInBackground() {
               sendFile();
          return null;
     public void sendFile() {
          System.out.printf("NOTICE: Sending file %s   %d bytes formed of %d segments.\n", file.getName(), file.length(), file.length()/bufferSize < 1 ? 1 : file.length()/bufferSize);
          try {
               fileIn = new FileInputStream(file);
               while ((bytesRead = fileIn.read(buffer)) > 0) {
                    output.write(buffer, 0 , bytesRead);
                    progress = progress + bufferSize;
                    if (progress  < file.length())
                         setProgress(progress);
                    else
                         setProgress((int)file.length());
               output.close();
               fileIn.close();
               socket.close();
          } catch (FileNotFoundException e) {
               e.printStackTrace();
          } catch (IOException ioe) {
               ioe.printStackTrace();
}This has been bugging me for a long time. Any help/suggestions much appreciated.

Answer 1

when you create an SSCCE and get rid of all the File, socket, streams and whatnot (something that you should do next time), you notice something funny:
import java.awt.BorderLayout;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
public class FileTracker extends JDialog implements PropertyChangeListener
    private static final int MAX = 500;
    private JPanel progressBarPnl = new JPanel(new BorderLayout());
    private JProgressBar progressBar;
    private FileSender fileSender;
    private FileReceiver fileReceiver;
    public FileTracker(JFrame parent)
        super(parent);
        fileSender = new FileSender(MAX);
        fileSender.addPropertyChangeListener(this);
        fileSender.execute();
        setLocationRelativeTo(null);
        progressBar = new JProgressBar();
        progressBar.setMaximum(MAX);
        add(progressBarPanel());
        setResizable(false);
        setTitle("File sending..");
        pack();
        //setVisible(true);
    private JPanel progressBarPanel()
        progressBar.setValue(0);
        progressBar.setEnabled(true);
        progressBar.setStringPainted(true);
        progressBar.setIndeterminate(true);
        progressBarPnl.add(progressBar, BorderLayout.CENTER);
        return progressBarPnl;
    public void propertyChange(PropertyChangeEvent evt)
        //if ("progress" == evt.getPropertyName()) // *** avoid doing this
        if ("progress".equals(evt.getPropertyName()))
            int progress = (Integer) evt.getNewValue();
            progressBar.setValue(progress);
            System.out.println("progress is: " + progress);
            if (fileSender != null && fileSender.isDone())
                progressBar.setString("Transfer finished");
                System.out.println("file sender is done");
            if (fileReceiver != null && fileReceiver.isDone())
                progressBar.setString("Transfer finished");
                System.out.println("file receiver is done");
    private class FileReceiver
        public boolean isDone()
            return false;
    private class FileSender extends SwingWorker<Void, Void>
        private int max;
        private int bufferSize;
        int bytesRead;
        int progress = 0;
        public FileSender(int max)
            this.max = max;
            System.out.println("NOTICE: FileSender initialised. ");
            bufferSize = max;
            setProgress(0);
        public Void doInBackground()
            sendFile();
            return null;
        public void sendFile()
            System.out.println("NOTICE: Sending file ");
            System.out.println("Max = " + max);
            bufferSize = 10;
            while (progress < max)
                try
                    Thread.sleep(100);
                catch (InterruptedException e)
                    e.printStackTrace();
                progress += bufferSize;
                if (progress < max)
                    setProgress(progress);
                else
                    setProgress(max);
            System.out.println("after while loop");
    private static void createAndShowUI()
        JFrame frame = new JFrame("FileTracker");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        FileTracker filetracker = new FileTracker(frame);
        filetracker.setVisible(true);
    public static void main(String[] args)
        java.awt.EventQueue.invokeLater(new Runnable()
            public void run()
                createAndShowUI();
}The SwingWorker stops when only 20% of "file transfer" has occurred, but when the progress has reached 100. Then if you go into the [SwingWorker API for setProgress|http://java.sun.com/javase/6/docs/api/javax/swing/SwingWorker.html#setProgress(int)] , you see why the program is stopping here: the SwingWorker stops when its progress property reaches 100. So you must change this to a ratio rather than total bytes.