Question

I have been trying to fix the following problem for weeks :(. In my Java applet (MyApplet) I have a method, for a button, called btnSendToPC which is supposed to send selected file contents from server to local PC through an open socket. The problem occurs when I try to implement a JProgressBar that will show user how much of that file has been downloaded to local PC. I read many JProgressBar examples on this site but I honestly still can not figure it out. I would be very grateful if you helped me out. The following is a very short version of my code including all the major parts.

//My Network class that opens a socket and reads bytes from the socket
public class TcpIp {

    protected Socket s = null;
    public DataInputStream dis = null;

    public TcpIp(InetAddress ipa, int port) {

        try { 
            s = new Socket(ipa.getHostAddress(), port);
        } catch (IOException ex) {
            System.out.println("Error opening socket!");
            return;
        }

        try { //Create an input stream.
            dis = new DataInputStream(new BufferedInputStream(s.getInputStream()));
        } catch (Exception ex) {
            System.out.println("Error creating input stream!");
        }

    }

    public synchronized byte[] readBytes() throws IOException {

        ByteArrayOutputStream getBytes = new ByteArrayOutputStream();

        int oneByte;

        while ((oneByte = dis.read()) != 124) {//Reads 1 byte from the InputStream and breaks on | character
            getBytes.write(oneByte);
        }

        return (getBytes.toByteArray());

    }
}

//My main Applet class that has the method for Send to PC button
public class MyApplet extends javax.swing.JApplet implements Runnable {

    public TcpIp gtp = null;
    private static String inGet;

    @Override
    public void run() {

        int i;

        byte[] in = new byte[10000024];

        try {
            Thread.sleep(1000);
            //pause gtp.readBytes so that server has enough time to receive name of the file to read,
            //to read its contents and send its contents back through socket
        } catch (InterruptedException ex) {
        }

        if ((gtp != null)) {

            try {
                in = gtp.readBytes();
            } catch (IOException ex) {
            }

            //Remove non-printing bytes.
            for (i = 0; i < in.length; i++) {
                if (in[i] < 0x20) {
                    in[i] = 0x20;
                }
            }

            inGet = new String(in);
        }
    }

    public void btnSendToPC() {

        //In here are commands that send name of the file to read. 
        //Server reads that file and sends its contents back through socket.

        try {

            FileOutputStream fout = new FileOutputStream(fn);
            BufferedWriter myOutput = new BufferedWriter(new OutputStreamWriter(fout));

            timer = new Thread(this);
            timer.start();

            try {
                timer.join();
            } catch (InterruptedException ex) {
            }

            myOutput.write(inGet)

            myOutput.close();
            fout.close();
        }

    }
}

Answer 1

Just use a javax.swing.ProgressMonitorInputStream. Does all the hard work for you.