Why paintComponenet() method is not invoked by the run function?

I am coding a 2d game using Java. I have created 2 classes: Main class and Game Panel class. paintComponenet() method is not invoked as expected. Below is the code.

package main;

import javax.swing.JFrame;

public class Main {

    public static void main(String[] args) {

        JFrame window = new JFrame();
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.setResizable(false);
        window.setTitle("2D Adventure");

        GamePanel gamePanel = new GamePanel();

        window.add(gamePanel);
        window.pack();

        window.setLocationRelativeTo(null);
        window.setVisible(true);

        gamePanel.startGameThread();

    }
}

package main;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import javax.swing.JPanel;

public class GamePanel extends JPanel implements Runnable {

    //SCREEN SETTINGS
    final int originalTileSize = 16; //16x16 Tile
    final int scale = 3;

    final int tileSize = originalTileSize * scale; //48x48 Tile
    final int maxScreenCol = 16;
    final int maxScreenRow = 12;
    final int screenWidth = tileSize * maxScreenCol; //768 pixels
    final int screenHeight = tileSize * maxScreenRow; //576 pixels

    Thread gameThread;

    public GamePanel() {
        this.setPreferredSize(new Dimension(screenWidth, screenHeight));
        this.setBackground(Color.black);
        this.setDoubleBuffered(true);
    }

    public void startGameThread() {
        gameThread = new Thread(this);
        gameThread.start();
    }

    @Override
    public void run() {
        while (gameThread != null) {
            System.out.println("The game thread is running");
//            1. UPDATE: update character information
            update();
//            2. DRAW: draw the character at fps
            repaint();
        }
    }

    public void update() {
        System.out.println("Update method called");
    }

    public void paintComponenet(Graphics2D g) {
        System.out.println("paintComponent method called");
        super.paintComponent(g);

        Graphics2D g2 = (Graphics2D) g;
        g2.setColor(Color.white);
        g2.fillRect(100, 100, tileSize, tileSize);

        g2.dispose();
    }

}

While the thread is running, I get,

The game thread is running
Update method called.

I am expecting a window with a black background and a white color square at 100, 100.

>Solution :

When overriding it, you misspelled it. It should be paintComponent(Graphics g)
It is also takes a Graphics instance.

  @Override
  public void paintComponent(Graphics g) {
        System.out.println("paintComponent method called");
        super.paintComponent(g);

        Graphics2D g2 = (Graphics2D) g;
        g2.setColor(Color.white);
        g2.fillRect(100, 100, tileSize, tileSize);

    }

To ensure you override the proper method, use that @Override annotation as I did above. Then if you misspell it, the compiler will complain. This is true for overriding any method.