Question

I have two class fils upload.java and transferProgress.java. upload.java makes applet GUI and uploads file to remote SSH server. transferProgress.java class gives transfer percentage. The upload percentage completed can be seen in console, but i wanted it to be seen on TextArea and on java progress bar. So i made transferProgress.java to inherit upload.java and append into TextArea.

My problem is, TextArea and JProgressBar do not get updated during the file transfer, but gets updated only when the file transfer is completed. After transfer completion, TextArea shows the log and JProgressBar get set to 100%. My code does not updates TextArea and JProgressBar during file transfer.

If i use setText() instead of append for updating TextArea, i can see real time progress update, but still ProgressBar do not get updated on real time.

I could not figure out where the problem is. I will be very thankful to your help.

upload.java

package biforce;
import java.applet.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.*; 
import java.io.*; 


import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;


public class upload extends Applet
{

  String filename;
  int port = 22;
  String user = "root";
  String password = "mypass";
  String host = "192.168.0.5";
  String knownHostsFile = "/home/bishwo/.ssh/known_hosts";
  String sourcePath = "";
  String destPath = "/media/dfs/gwas/";

  JTextField txtField = new JTextField(20);
  static TextArea txtArea;
  static JProgressBar progressBar;

    @Override
  public void init(){

  // text Field     
  txtField.setEditable(false);
  txtField.setText("");

  // text area
  txtArea = new TextArea(4,40);
  txtArea.setEditable(false);

  // JprogressBar
  progressBar = new JProgressBar(0, 100);
  progressBar.setValue(0);
  progressBar.setStringPainted(true);

  // Label
  JLabel fileLabel = new JLabel("File");

  // buttons
  JButton upload = new JButton( "Upload" );
  JButton browse = new JButton( "Browse" );

  // browse file to be uploaded
  browse.addActionListener( 
      new ActionListener()
      {
            @Override
        public void actionPerformed( ActionEvent ae )
        {
          JFileChooser fc = new JFileChooser();
          fc.setCurrentDirectory( new File( "/home/bishwo/Desktop/" ) );
          int returnVal = fc.showOpenDialog( upload.this ); 
          String filePath="";
          if ( returnVal == JFileChooser.APPROVE_OPTION )   
          {  
            File aFile = fc.getSelectedFile();  
            filePath = aFile.getAbsolutePath(); 
            filename = aFile.getName();
          }
          txtField.setText(filePath);
        }
      });
  // upload the browsed file
  upload.addActionListener( 
      new ActionListener()
      {
            @Override
        public void actionPerformed( ActionEvent ae )
        {

          if(txtField.getText().length()==0)
          {
              JOptionPane.showMessageDialog(upload.this,"Please select a file to upload.","Error", JOptionPane.ERROR_MESSAGE);
          }
          else
          {
            try
            {
                sourcePath=txtField.getText();
                JSch jsch = new JSch();
                jsch.setKnownHosts(knownHostsFile);
                Session session = jsch.getSession(user, host, port);
                session.setPassword(password);
                session.connect(); 

                ChannelSftp sftpChannel = (ChannelSftp) session.openChannel("sftp");
                sftpChannel.connect();

                txtArea.setText("Uploading..");
                transferProgress progress = new transferProgress();
                sftpChannel.put( sourcePath,destPath+filename, progress);      
                System.out.println("\nUpload Completed");  

                sftpChannel.exit();
                session.disconnect();
                JOptionPane.showMessageDialog(upload.this,"Upload completed successfully.","Info", JOptionPane.INFORMATION_MESSAGE);

            }
            catch(Exception e)
            {
                JOptionPane.showMessageDialog(upload.this,e,"Error", JOptionPane.ERROR_MESSAGE);
            }
          }
        }
      });

  add(fileLabel);
  add(txtField,"center");
  add(browse);
  add(upload);
  add(progressBar);
  add(txtArea);
  }

}

transferProgress.java

import com.jcraft.jsch.*;

public class transferProgress extends upload implements SftpProgressMonitor
{
    public double count=0;
    private int percentage;
    public double totalSize;
    private int lastPercentage;
    @Override
    public void init(int op, String src, String dest, long max) 
        {
        this.totalSize=max;
        }

    @Override
    public boolean count(long count) 
        {
        this.count += count;
        this.percentage = (int) ((this.count / this.totalSize) * 100.0);
        if (this.lastPercentage <= this.percentage - 5) 
            {
            this.lastPercentage= this.percentage;
            // setValue() does not work
            biforce.upload.progressBar.setValue(20);
            // append() does not work
            biforce.upload.txtArea.append(Integer.toString(this.percentage));
            // displays percentage completion on console
            System.out.println("Upload Completion "+this.percentage+" %");

            }
        return true;
        }

    @Override
    public void end() 
        {
        System.out.println("Total Copied "+this.percentage+" %");
        }
}

Answer 1

count() method from transferProgress class gives progress percentage 20 times until the file gets uploaded.

In my case SwingUtilities.invokeLater did not work out. I used SwingWorker, executed from upload class and it worked.
(P.S – i made progressBar in the class upload ‘public’)

public class uploadWorker extends SwingWorker<Integer, Integer>
{
    @Override
        protected Integer doInBackground() throws Exception
        {
                //some codes .....

                try{sftpChannel.put(upload.sourcePath,upload.destPath, new transferProgress()); }
               catch(Exception e){System.out.println(e);}

                Thread.sleep(1000);
                return 42;
        }

        protected void done()
        {

                System.out.print("done");

        }
}