import java.awt.Color;
import java.awt.Graphics;
import java.util.Random;
import javax.swing.JPanel;
import javax.swing.Timer;

public class Saver1JPanel extends JPanel
{
   private Random generator = new Random();
  
   // draw lines
   public void paintComponent( Graphics g )
   {
         
         
      super.paintComponent( g ); // call superclass's paintComponent
      
      int x1, y1, x2, y2;
      
      // draw 100 random lines
      for ( int i = 0; i < 100; i++ )
      {
         x1 = generator.nextInt( 700 );
         y1 = generator.nextInt( 700 );
         x2 = generator.nextInt( 700 );
         y2 = generator.nextInt( 700 );

         g.setColor( new Color( generator.nextInt( 256 ),
            generator.nextInt( 256 ), generator.nextInt( 256 ) ) );
         g.drawLine( x1, y1, x2, y2 );
        
        
  
      } // end outer for

      repaint(); // repaint component
   } // end method paintComponent
} // end class Saver1JPanel

import javax.swing.JFrame;

public class Saver
{
   // execute application
   public static void main( String args[] )
   {
      // create frame for Saver1JPanel
      JFrame frame = new JFrame( " Line ScreenSaver " );
      frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

      // create Saver1JPanel
      Saver1JPanel saver1JPanel = new Saver1JPanel();
      frame.add( saver1JPanel ); // add saver1JPanel to frame
      frame.setSize( 700, 700 ); // set frame size
      frame.setVisible( true ); // display frame
   } // end main
} // end class Saver

      repaint(); // repaint component
      try { Thread.sleep(100); } catch( InterruptedException e) {}

// Get current time
timeStep = System.currentTimeMillis();

// Hold to lock at FPS
while(System.currentTimeMillis()-timeStep < 1000/60);