Also available as Simple.java

/**
 * A Simple stand-alone GUI program based on Swing.
 * The program just displays a simple message.
 *
 * @author Dave Hollinger
 * @version 1.0
 */

import javax.swing.*;

class Simple {
  static private final String label = "Hello World";
  static private final String title = "Simple Java GUI";

  public static void main(String [] args) {
        // create a top-level container with a title
        JFrame frame = new JFrame(title);

        // set the size
        frame.setSize(200,200);

        // establish what happens when the window is closed
        // (without this the program would keep running!)
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // create a label
        JLabel lbl = new JLabel(label);

        // add the label to the frame (to the content pane of the frame)
        frame.getContentPane().add(lbl);

        // make the frame visible

        frame.setVisible(true);

  }

}