Repaint() don't call PaintComponent()

Newbie & Debugging Questions
#1

Hi , post simple code , i have put in PaintComponent() a System.out.println() to see if enter in the code when i call repaint() and the answer is no , so repaint don’t call PaintComponent() why??:

import javax.net.ssl.KeyManager;
import javax.swing.JFrame;
import java.awt.GridLayout;

public class Frame extends JFrame{



    public Frame(){
       GamePanel g = new GamePanel();
       add(g);
       setTitle("Frame");
       setSize(200,200);
       setResizable(false);
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       setVisible(true);
    }

    public static void main(String[] args) {
        Frame F= new Frame();
    }
}

import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;

public class GamePanel  extends JPanel implements Runnable{

public static Thread thread;


public GamePanel(){
    setBackground(Color.WHITE);
    thread=new Thread(this);
    thread.start();
}

public void PaintComponent(Graphics g){
   System.out.println("into");
   g.setColor(new Color(100,100,100));
   g.fillRect(0,0,100,100);
}

public void run(){
   while(true){
   repaint();
   try{
   thread.sleep(1000);
   }catch(InterruptedException e){}
   }
}


}