Frame0.java
Created with JBuilder
package view;

import javax.swing.*;  // to use JFrame.

/**
 * Minimal reusable code to create a JFrame with a title and a window event
 * listener to call on System.exit() and force termination of the main
 * application that creates this JFrame.
 * @author D.X. Nguyen
 */
public class Frame0 extends JFrame {

    public Frame0(String title) {
        // Always call the superclass's constuctor:
        super(title);

        // Add an anonymous WindowAdapter event handler to call System.exit to
        // force termination of the main application when the Frame closes.
        // Without it, the main application will still be running even after
        // the frame is closed.
        // For illustration purpose, we use the full package name for
        // WindowAdpater and WindowEvent.
        // We could have imported java.awt.event.* and avoid using the full
        // package names.
        addWindowListener(new java.awt.event.WindowAdapter() {
            public void windowClosing(java.awt.event.WindowEvent e) {
                System.out.println(e);
                System.exit(0);
            }
        });

        initialize();
    }

    protected void initialize() {
        // Does nothing here.
        // Subclasses may do more.
    }
}

Frame0.java
Created with JBuilder