I have created a for loop that counts from 0 to 850000. I have chosen a high number because I want to create a progress bar that will update using the results in the for loop. Here is the code that I have so far.
public class ProgressBarTest extends JFrame {
private JPanel contentPane;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
ProgressBarTest frame = new ProgressBarTest();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public ProgressBarTest() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
for(int i = 850000; i>0; i--) {
System.out.println("i = " + i);
}
}
}
I cannot seem to find a way to get a progress bar to update using a for loop. I did create a progress bar that worked on a timer but that is not what I want it to do. I basically want it to update from 0% to 100%. This does seem simple to me but I have been stuck on it for a while. I appreciate any sort of sample code that will help me to understand how it works.
Here is the complete example, using SwingWorker
proposed by the Saran
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
import javax.swing.border.EmptyBorder;
public class ProgressBarTest extends JFrame {
private static final long LOOP_LENGTH = 85000000;
private JPanel contentPane;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
ProgressBarTest frame = new ProgressBarTest();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public ProgressBarTest() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
JProgressBar progress = new JProgressBar();
progress.setStringPainted(true);
contentPane.add(new JLabel("Loop progress is: "), BorderLayout.NORTH);
contentPane.add(progress, BorderLayout.SOUTH);
setContentPane(contentPane);
ProgressWorker worker = new ProgressWorker(progress);
worker.execute();
}
private static class ProgressWorker extends SwingWorker<Void, Integer> {
private final JProgressBar progress;
public ProgressWorker(JProgressBar progress) {
this.progress = progress;
}
@Override
protected Void doInBackground() throws Exception {
for (long i = LOOP_LENGTH; i > 0; i--) {
final int progr = (int) ((100L * (LOOP_LENGTH - i)) / LOOP_LENGTH);
publish(progr);
}
return null;
}
@Override
protected void process(List<Integer> chunks) {
progress.setValue(chunks.get(chunks.size() - 1));
super.process(chunks);
}
@Override
protected void done() {
progress.setValue(100);
}
}
}