SwingWorker is ideal for this. The example below performs a simple iteration in the background, while reporting progress and intermediate results in a window. You can pass whatever parameters you need in a suitable SwingWorker constructor.
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.text.DecimalFormat;
import java.util.List;
import javax.swing.*;
/** @see http://stackoverflow.com/questions/4637215 */
public class TwoRoot extends JFrame {
private static final String s = "0.000000000000000";
private JProgressBar progressBar = new JProgressBar(0, 100);
private JLabel label = new JLabel(s, JLabel.CENTER);
public TwoRoot() {
this.setLayout(new GridLayout(0, 1));
this.setTitle("√2");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(progressBar);
this.add(label);
this.setSize(161, 100);
this.setLocationRelativeTo(null);
this.setVisible(true);
}
public void runCalc() {
progressBar.setIndeterminate(true);
TwoWorker task = new TwoWorker();
task.addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent e) {
if ("progress".equals(e.getPropertyName())) {
progressBar.setIndeterminate(false);
progressBar.setValue((Integer) e.getNewValue());
}
}
});
task.execute();
}
private class TwoWorker extends SwingWorker<Double, Double> {
private static final int N = 5;
private final DecimalFormat df = new DecimalFormat(s);
double x = 1;
@Override
protected Double doInBackground() throws Exception {
for (int i = 1; i <= N; i++) {
x = x - (((x * x - 2) / (2 * x)));
setProgress(i * (100 / N));
publish(Double.valueOf(x));
Thread.sleep(1000); // simulate latency
}
return Double.valueOf(x);
}
@Override
protected void process(List<Double> chunks) {
for (double d : chunks) {
label.setText(df.format(d));
}
}
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
TwoRoot t = new TwoRoot();
t.runCalc();
}
});
}
}