ch02/rectangles/RectangleViewer.java
 import javax.swing.JFrame;

 public class RectangleViewer
 {
 public static void main(String[] args)
 {
 JFrame frame = new JFrame();
 frame.setSize(300, 400);
 frame.setTitle(Two rectangles);
 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

 RectangleComponent component = new RectangleComponent();
 frame.add(component);

 frame.setVisible(true);
 }
 }