Не срабатывает метод repaint (Java)

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
public class GameField extends JPanel implements ActionListener {
static Image part;
static Image apple;
private Timer timer;
public static int sizeX = 480;
public static int sizeY = 480;
public static int sizePart = 16;
public static int headX;
public static int headY;
public static int size;
private int pointX[] = new int[sizeX];
private int pointY[] = new int[sizeY];
public GameField() {
    setBackground(Color.black);
    loadImages();
    size = 1;
    pointX[0] = 16;
    pointY[0] = 0;
    timer = new Timer(250, this);
    timer.start();
    setVisible(true);
}
public void move() {
    System.out.println("флуд");
    for (int i = size; i > 0; i--) {
        pointX[i] = pointX[i - 1];
        pointY[i] = pointY[i - 1];
    }
}
private void loadImages() {
    part = new ImageIcon("part.png").getImage();
    apple = new ImageIcon("apple.png").getImage();
}
@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    System.out.println("Это сообщение будет выведено только один раз");
    for (int i = 0; i <= size; i++) {
        g.drawImage(part, pointX[i], pointY[i], this);
    }
}
    @Override
        public void actionPerformed(ActionEvent arg0) {
        while (true) {
            move();
            repaint();// !!! ??? не срабатывает
        }
}
}