Thread: help me!

Arrrgh! This is hopeless! My dream is to be a game developer, and I have tried to make a simple 2D game. Every single time, I tell you, every single time, I get stuck with something. Before my imageIO hasn't been working, so I decided to make a game with only javas Graphics2D. Just when I got started I encounter a problem, my game loop doesn't work. I use a simple Thread game loop. I put print messages in my code to debug that way. The loop runs once and then stop! Why?

Here is my code:

package shooter;
 
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
 
import javax.swing.JPanel;
 
public class GamePanel extends JPanel implements Runnable {
 
	private boolean paused = false;
	private boolean gameover = false;
	private int playerX, playerY, playerW, playerH, playerDx;
	private Thread thread;
 
	public GamePanel() {
		thread = new Thread(this);
 
		playerX = Game.WIDTH / 2 - 15;
		playerY = 360;
		playerW = 30;
		playerH = 20;
 
		addKeyListener(new KeyL());
 
		thread.start();
	}
 
	public void paint(Graphics gf) {
 
		Graphics2D g = (Graphics2D)gf;
 
		//paints the background.
		g.setColor(Color.BLACK);
		g.fillRect(0, 0, Game.WIDTH, Game.HEIGHT);
 
		//paints the player
		g.setColor(Color.WHITE);
		g.fillRect(playerX, playerY, playerW, playerH);
 
		System.out.println("painted!");
	}
 
	//game loop
	@Override
	public void run() {
		move();
		repaint();
 
		System.out.println("looped!");
		try {
			Thread.sleep(17);
		}catch(Exception ex){
			System.out.println(ex);
		}
	}
 
	//checks all collisions in game
	public void checkCollisions() {
 
		//checks if the player its the walls.
		if (playerX + playerDx < 0) {
			playerX = 0;
			playerDx = 0;
		}
		else if (playerX + playerDx > Game.WIDTH) {
			playerX = Game.WIDTH - playerW;
			playerDx = 0;
		}
	}
 
	//moves all entities.
	public void move() {
		playerX += playerDx;
		System.out.println("Moved!");
	}
 
	private class KeyL extends KeyAdapter {
 
		public void keyPressed(KeyEvent e) {
			int key = e.getKeyCode();
 
			if (key == KeyEvent.VK_A) {
				playerDx = -2;
				System.out.println("moving left");
			}
			if (key == KeyEvent.VK_D) {
				playerDx = 2;
				System.out.println("moving right");
			}
		}
	}
}

Yes, I know there is no main class. That one is in the JFrame class but I know the error isn't there.

This is very frustrating! Earlier I have just given up, but know I decided to get help instead.

Please, please, PLEASE, help me!

P.S. The controls doesn't work either.

A Thread's run() method is only called once, not repeatedly. If you want it to run more than once, you have to set up a loop inside of it.

I would recommend that you use a Swing Timer instead though.

You need to set the focus to the JPanel,
Make it focusable first and then request the focus.

You may also want to make it so the player stops moving when the keys are released. Unless your intent was to have them always moving.