Graphics in Java

/**Graphics In Java Example **/

import java.awt.*;
import java.awt.event.*;

class line extends Frame implements MouseListener,ActionListener
 {

     int x1,x2,y1,y2;
     Button b;
   
public line()
 {
 
    addMouseListener(this);
                 b=new Button("EXIT");

     setLayout(new FlowLayout());
                    add(b);
                       b.addActionListener(this);
 }

public void actionPerformed(ActionEvent ae)
 {

     System.exit(0);
 }


public void mousePressed(MouseEvent me)
 {
    x1=me.getX();
    y1=me.getY();
 }

public void mouseReleased(MouseEvent me)
 {
    x2=me.getX();
    y2=me.getY();
 
    Graphics g=getGraphics();

   g.drawLine(x1,y1,x2,y2);
}

public void mouseClicked(MouseEvent me)
 {
 }

public void mouseEntered(MouseEvent me)
 {
 }

public void mouseExited(MouseEvent me)
 {
 }

public static void main(String args[])throws Exception
 {

     line l=new line();

    l.setSize(600,600);
    l.setVisible(true);
}

    }