Help please!!!!!

Im having trouble. Whenever I try to run this code, it closes right away and I can't figure out why and i want to figure this out.

Heres the code:

import java.util.Random;

import java.util.Scanner;

import java.awt.*;

import javax.swing.*;

import javax.swing.JFrame;

import javax.swing.JPanel;

class magic8ball extends JPanel {

public static void main(String[] args)

{

int number;

Random myRandom = new Random();

Scanner myScanner = new Scanner(System.in);

number = myRandom.nextInt(1) + 1;}

public void paintComponent1(Graphics g) {

Random myRandom = new Random();

int number = myRandom.nextInt(1) + 1;;

switch (number)

{

case 1:

g.setColor(Color. MAGENTA);

g.fillRect(0,0,3000,3000);

g.setColor(Color. black);

g.fillOval(300,300,100,100);

break;

}

}

public magic8ball () {

}

public void paintComponent(Graphics g) {

super.paintComponent(g);

{

}

}

{

magic8ball t = new magic8ball();

JFrame jf = new JFrame();

jf.setTitle("box");

jf.setSize(600,400);

jf.setVisible(true);

jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

jf.add(t);

}

}