Internal Frame in Core Java

While doing my college project i find this example to be very useful to use internal frame as MDI child. It is a simple example where internal frame is made visible and invisible to make MDI possible.

//File Name JIFDemo.Java
 * @author prashant-lappy
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class JIFDemo extends JFrame{

 public static void main(String [] args){
 new JIFDemo();

 public JIFDemo()
 // Create an internal frame
 boolean resizable = true;
 boolean closeable = true;
 boolean maximizable  = true;
 boolean iconifiable = true;
 String title = "Frame Title";
 JInternalFrame iframe = new JInternalFrame(title, resizable, closeable, maximizable, iconifiable);

 // Set an initial size
 int width = 200;
 int height = 50;
 iframe.setSize(width, height);

 // By default, internal frames are not visible; make it visible

 // Add components to internal frame...
 iframe.getContentPane().add(new JTextArea("Hello"));

 // Add internal frame to desktop
 JDesktopPane desktop = new JDesktopPane();

 // Display the desktop in a top-level frame
 getContentPane().add(desktop, BorderLayout.CENTER);
 setBounds(100, 100, 300, 300);