Create a JProgressBar Component with an Unknown Maximum in Java

//  w  w w.  j a  va2  s  .c  o  m

import java.awt.BorderLayout;

import javax.swing.JFrame;
import javax.swing.JProgressBar;

public class Main extends JFrame {

  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    int min = 0;
    int max = 100;
    JProgressBar progress = new JProgressBar(min, max);

    // Play animation
    progress.setIndeterminate(true);
    
    getContentPane().add(progress, BorderLayout.NORTH);
    pack();
    setVisible(true);
  }

  public static void main(String arg[]) {
    new Main();
  }
}