Hey guys I am creating a screensaver program which displays random shapes,lines and colours etc. I have started entering the code but the program isn't showing up the random shapes and colours, please help

Here is the code:

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

public class ScreenSaver {

JFrame frame = new JFrame("ScreenSaver");
JPanel panel = new JPanel();

ScreenSaverPanel screensaverpanel = new ScreenSaverPanel();

public static void main (String [] args) {

ScreenSaver gui = new ScreenSaver ();
gui.go();
}
public void go() {

ScreenSaver drawpanel = new ScreenSaver();

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOS E);

frame.add(panel);

frame.setSize(800,800);

frame.setVisible(true);
}
class ScreenSaverPanel extends JPanel {
public void paintComponent(Graphics g)
{
int x1, y1, x2, y2;

for(int i = 0; i < 100; i++)
{
x1 = (int) (Math.random() * 256);
y1 = (int) (Math.random() * 256);
x2 = (int) (Math.random() * 256);
y1 = (int) (Math.random() * 256);
}

g.setColor(Color.black);

g.fillRect(30, 50, 70, 100);

Color someColor = new Color(x,y,x);

g.setColor(someColor);

g.fillOval(10, 10, 90, 100);
}
panel.repaint();
}
}

Any suggestions plz

i think that i need to use a loop so that the program keeps displaying random shapes and colors just like a screensaver would