Witam, tak jak w tytule :)

package SnakeP;

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;

import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import java.awt.Panel;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class SnakeFrame {

	private JFrame frame;

	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					SnakeFrame window = new SnakeFrame();
					window.frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	public SnakeFrame() {
		initialize();
	}

	private void initialize() {
		frame = new JFrame();
		frame.setBounds(100, 100, 500, 500);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setTitle("Snake");
		
		JPanel panel = new JPanel();
		panel.getRootPane().add(panel, BorderLayout.CENTER); {
			public void paintComponent(Graphics g) { //tutaj pojawia się problem :/
				super.paintComponent(g);
				g.drawRect(100, 100, 100, 100);
				g.setColor(Color.BLACK);
			}
			
		}
		
		
		

		}
	}