How can i get ProgressMonitor to display while task is going on.

Question

hi can anybody tell me what i'm doing wrong.. I don't understand threads that well. I'm writing ftp client that uploads user files to our ftp.server. My problem is ProgressMonitor hangs until ftp transfer is done before displaying message of the job status... I try to give it it's own thread. but it seems like the process for ftp upload takes higher priority so ProgressMonitor does not get attention til all ftp process is done...
import java.io.*;
import java.util.List;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import sun.net.ftp.*;
import sun.net.*;
* An application that displays a ProgressMonitor
* when the 'Upload' button is pressed. A complex
* 'operation' to upload files and update the monitor
* @author
public class ProgressTestApp extends JApplet {
private JPanel actionPanel;
private String names[] = { "browse..","Upload" };
private JButton choices[];
private JLabel label;
private JTextField FolderpathText;
private JPanel reportPanel;
private String newline = "\n";
private JTextArea taskOutput;
private File pwFile;
private ProgressMonitor monitor;
private String fullpath;
private List mylist;
Thread thread = new Thread();
JFrame frame = new JFrame( "Progress-Monitor" );
private int mini=0;
public int maxi=100;
public int boo=0;
private Runnable runnable;
/** a lable for the lient info text **/
private JLabel getclientLabel()
     if ( label == null )
     label = new JLabel("Directory to upload: ") ;
     return label;
/** a text to show client info */
private JTextField getFolderpathText()
if ( FolderpathText == null)
     FolderpathText = new JTextField (100);
     FolderpathText.setText( " " );
     return FolderpathText;
/** a text to show client info */
private JTextArea gettaskOutput()
if ( taskOutput == null)
     taskOutput = new JTextArea(5, 20);
taskOutput.setMargin(new Insets(5,5,5,5));
taskOutput.setEditable(false);
     return taskOutput;
private JPanel getreportPanel()
if (reportPanel == null)
     reportPanel = new JPanel(new BorderLayout());
     reportPanel.add(getclientLabel(),BorderLayout.WEST);
     reportPanel.add(getFolderpathText(),BorderLayout.CENTER);
return reportPanel;
* Application entry point.
* Create the splash window, and display it.
* @param args Command line parameter. Not used.
public void init() {
// Create a frame with a single button in it.
// When the button is pressed, a thread is spawned
// to run out sample operation.
//JFrame frame = new JFrame( "ProgressMonitor Test" );
//create array of buttons
choices = new JButton[names.length];
//set up panel for buttons
actionPanel = new JPanel();
actionPanel.setLayout( new GridLayout(1,choices.length));
//set up buttons and register their listeners
for ( int count = 0; count < choices.length; count++ )
choices[count]=new JButton(names[count]);
     actionPanel.add(choices[count]);
Container container = getContentPane();
container.setBackground(Color.gray);
container.add( getreportPanel(), BorderLayout.NORTH);
container.add( actionPanel, BorderLayout.CENTER);
// Create a ProgressMonitor. This will be started
// when the Upload button is pressed.
int min = mini;
int max = maxi;
String[] message = new String[2];
message[0] = "Performing Operation.";
message[1] = "This may take some time...";
final ProgressMonitor monitor = new ProgressMonitor( frame,
     message,
     " of ",
     min,
     max );
// This is our sample operation.
final Runnable runnable = new Runnable() {
public void run() {
if( boo == 1 )
maxi=file_utility(pwFile);
int sleepTime = 1000;
for( int i = 1; i < maxi; i++ ) {
try {
monitor.setNote( i + " of " + maxi );
monitor.setProgress( i );                              monitor.setMinimum( i );                              monitor.setMaximum( maxi );
if( monitor.isCanceled() ) {
monitor.setProgress( maxi );
break;
Thread.sleep( sleepTime );
catch( InterruptedException dontcare ) {
monitor.close();
choices[0].addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent event ) {
// Run the operation in its own thread.
pwFile=findfile();
     FolderpathText.setText(pwFile.getAbsolutePath());
     boo=1;
choices[1].addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent event ) {
// Run the operation in its own thread.
          Thread thread = new Thread( runnable );
          thread.start();
          ftp_utility(pwFile);
} // main
/*** Folder locater to find local file to upload ***/
File findfile()
     JFileChooser myFC = new JFileChooser();
     myFC.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
     int returnVal = myFC.showOpenDialog(new JFrame());
     if(returnVal == JFileChooser.APPROVE_OPTION)
     //JOptionPane.showMessageDialog( null, myFC.getSelectedFile());
     File file = myFC.getSelectedFile();
     //String fullpath=c.getSelectedFile().getName();
     return file;
/***Fi_l_e_s to upload ***/
public int file_utility (File uploadFile)
     int files=0;
     FtpClient fcMyFtp = new FtpClient();
     try
     int ch;
     fcMyFtp.openServer("ftp.abc.com");
     fcMyFtp.login("Anonymous","[email protected]");
     fcMyFtp.binary();
     fcMyFtp.cd("incoming40");
     if( uploadFile.isDirectory())
     if( mylist == null )
          mylist= Arrays.asList(uploadFile.list());
     catch (Exception exception)
     JOptionPane.showMessageDialog(null,exception);
     return mylist.size();
/***FT_P _ ***/
public void ftp_utility (File uploadFile)
FtpClient fcMyFtp = new FtpClient();
     try
     int ch;
     fcMyFtp.openServer("ftp.abc.com");
     fcMyFtp.login("Anonymous","[email protected]");
     fcMyFtp.binary();
     fcMyFtp.cd("incoming40");
     if( uploadFile.isDirectory())
     if( mylist == null )
     mylist= Arrays.asList(uploadFile.list());
     for(int count=0; count < mylist.size(); count++)
     fullpath=uploadFile.getAbsolutePath()+"\\"+mylist.get(count);
     File file = new File(fullpath);
     if( file.isDirectory())
     //file.mkdir();
     //ftp_utility(file);
     else
     TelnetOutputStream out = fcMyFtp.put(file.getName());
     FileInputStream in = new FileInputStream(file);
     int c = 0;
     while ((c = in.read()) != -1 )
          out.write(c);
     in.close();
     out.close();
     fcMyFtp.closeServer();
     //JOptionPane.showMessageDialog( null, "Upload completed...");
     catch (Exception exception)
     JOptionPane.showMessageDialog(null,exception);
} // ProgressTest

Answer 1

First of all, please use the code tags when posting code, especially that much code. http://forum.java.sun.com/faq.jsp#messageformat
The problem is that you need to switch the threads, so you should spawn the ftp process in a new thread, and let the monitor run in the main thread (actually the UI thread). I don't think that's really documented anywhere. I had the same problem the first time.