Animation - UPDATE FOR JFRAME

2 Ways that might make sense; you dont need buffergraphics because JPanel has it built in.

             
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;

public class TimerBasedAnimation extends JPanel implements Runnable {
 
  int x=0;

  public TimerBasedAnimation() {  
	  start();
    
  }

    public void paintComponent(Graphics g) {
    	super.paintComponent(g);
    	//g.clearRect(0, 0, 500, 500);
        x++;
        g.drawRect(x,40,50,50);
        g.setColor(Color.green);
        g.fillOval(x, 20, 20, 20);
  }

  

  public void update()
  {
      //put your code for what should happen each animation
	  repaint();
  }
   
   
  /*********************************************************************************************/
  /* BELOW IS FOR ANIMATION.  THE ONLY THING THAT YOU NEED TO CHANGE IS DELAY */
   
  int frame;
  int delay=20;   // this is the time of the delay in milliseconds.
  Thread animator;
   
  /**
   * This method is called when the applet becomes visible on
   * the screen. Create a thread and start it.
   */
  public void start()
  {
      animator = new Thread(this);
      animator.start();
  }
   
  /**
   * This method is called by the thread that was created in
   * the start method. It does the main animation.
   */
  public void run()
  {
      // Remember the starting time
      long tm = System.currentTimeMillis();
      while (Thread.currentThread() == animator)
      {
          // Display the next frame of animation.
          update();
          try
          {
              tm += delay;
              Thread.sleep(Math.max(0, tm - System.currentTimeMillis()));
          }
          catch (InterruptedException e)
          {
              break;
          }
          // Advance the frame
          frame++;
      }
  }
   
  /**
   * This method is called when the applet is no longer
   * visible. Set the animator variable to null so that the
   * thread will exit before displaying the next frame.
   */
  public void stop()
  {
      animator = null;
  }
  
  public static void main(String[] args) {
    JFrame frame = new JFrame("TimerBasedAnimation");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.add(new TimerBasedAnimation());
    frame.setSize(350, 250);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }
}

             
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;

public class CopyOfTimerBasedAnimation extends JPanel implements ActionListener {
 
  int x=0;

  Timer timer;

  public CopyOfTimerBasedAnimation() {  

    timer = new Timer(20, taskPerformer);
    timer.setInitialDelay(190);
    timer.start();
  }
  
  ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
    	  repaint();
      }
  };

  
    public void paintComponent(Graphics g) {
    	super.paintComponent(g);
    	g.clearRect(0, 0, 500, 500);
        x++;
        g.drawRect(x,40,50,50);
  }

  public void actionPerformed(ActionEvent e) {
      repaint();
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame("TimerBasedAnimation");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.add(new CopyOfTimerBasedAnimation());
    frame.setSize(350, 250);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }
}
        }