Painting in Swing

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
class Paint extends JPanel 
{
 Insets ins; 
 Random rand; 
 Paint() 
{
 setBorder(BorderFactory.createLineBorder(Color.RED, 5));
 rand = new Random();
}
protected void paintComponent(Graphics g) 
{
 super.paintComponent(g);
 int x, y, x2, y2;
 int height = getHeight();
 int width = getWidth();
 ins = getInsets();
for(int i=0; i < 10; i++) 
{
 x = rand.nextInt(width-ins.left);
 y = rand.nextInt(height-ins.bottom);
 x2 = rand.nextInt(width-ins.left);
 y2 = rand.nextInt(height-ins.bottom);
 g.drawLine(x, y, x2, y2);
}
}
}
class Painting
{
 JLabel jlab;
 Paint p1;
 Painting() 
{
 JFrame jfrm = new JFrame("Paint Demo");
 jfrm.setSize(200, 150);
 jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 p1 = new Paint();
 jfrm.add(p1);
 jfrm.setVisible(true);
}
public static void main(String args[]) 
{
 SwingUtilities.invokeLater(new Runnable() 
{
public void run() 
{
 new Painting();
}
});
}
}

Output: