import java.awt.Graphics;

import javax.swing.JComponent;
import javax.swing.JFrame;

public class ClassCastExceptionTest {


	 public static void main(String[] a) {
		    JFrame window = new JFrame();
		    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		    window.setBounds(30, 30, 300, 300);
		    window.getContentPane().add(new MyCanvas());
		    window.setVisible(true);
	}
	static class MyCanvas extends JComponent {

	  public void paint(Graphics g) {
	    g.drawRect (10, 10, 200, 200);  
	  }
	}



}