LOL

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Locura extends JComponent {

    private final static int ANCHO = 500, ALTO = 500;

    public Locura() {
        setPreferredSize(new Dimension(ANCHO, ALTO));
    }

    public void paint(Graphics g) {
        g.setColor(Color.BLACK);
        g.fillRect(0, 0, ANCHO, ALTO);
        g.setColor(Color.WHITE);
        g.fillOval( (int) (Math.random()*250+1), (int) (Math.random()*250+1), (int) (Math.random()*250+1), (int) (Math.random()*250+1) );
    }

    private void dibuja() throws Exception {
        SwingUtilities.invokeAndWait(new Runnable() {
                public void run() {
                    paintImmediately(0, 0, ANCHO, ALTO);
                }
            });
    }

    public void tiempo() throws Exception {
        long tiempoViejo = System.nanoTime();

        while (true) {
            long tiempoNuevo = System.nanoTime();
            float dt = (tiempoNuevo - tiempoViejo) / 1000000000f;
            tiempoViejo = tiempoNuevo;

            dibuja();
        }
    }

    public static void main(String[] args) throws Exception {
        JFrame jf = new JFrame("Locura");
        jf.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent e) {
                    System.exit(0);
                }
            });
        jf.setResizable(false);
        Locura locura = new Locura();
        jf.getContentPane().add(locura);
        jf.pack();
        jf.setVisible(true);
        locura.tiempo();
    }
}