java图形在绘制到屏幕时会滞后

Question

我松散地跟随this persons code做一个乒乓球游戏

但是，当我运行程序时，屏幕将显示1。变成纯白色，2。变白，几秒钟后，或3秒钟后，在屏幕上画画。立即在屏幕上涂色

我目前没有太多的代码。为什么有时在画框时会出现延迟？我该怎么解决这个问题？有更好的方法吗

[主要课程]

import javax.swing.JFrame;

public class Main extends JFrame {
public static final int FRAME_WIDTH = 900, FRAME_HEIGHT = 500;
GamePanel game;

public Main() {
    this.setTitle("Pong");
    this.setSize(FRAME_WIDTH, FRAME_HEIGHT);
    this.setDefaultCloseOperation(EXIT_ON_CLOSE);
    this.setLocationRelativeTo(null);
    this.setVisible(true);

    game = new GamePanel(this);
    add(game);

}

public static void main(String[] args) {
    Main main = new Main();

}

public int getWidth() {
    return FRAME_WIDTH;
}

public int getHeight() {
    return FRAME_HEIGHT;

}

}

[游戏面板]

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;

import javax.swing.JPanel;

public class GamePanel extends JPanel {
private Main main;
private Player player;
private int playerScore = 0;
private int oppScore = 0;

private int yCenter;

public GamePanel(Main main) {
    setBackground(Color.BLACK);
    this.main = main;
    this.yCenter = (main.getHeight() / 2) - 75;
    player = new Player(main, 25, yCenter);

}

public void paintComponent(Graphics g) {
    super.paintComponent(g);
    g.setColor(Color.WHITE);
    g.setFont(new Font("Courier", Font.BOLD, 40));
    g.drawString(playerScore + " - " + oppScore, (main.getWidth() / 2) - 75, 50);

    player.draw(g);

}

}

[玩家等级]

import java.awt.Graphics;

public class Player {
private Main main;
private static final int PLAYER_WIDTH = 30, PLAYER_HEIGHT = 125;
private int x, y;

public Player(Main main, int x, int y) {
    this.main = main;
    this.x = x;
    this.y = y;

}

public void draw(Graphics g) {
    g.fillRect(x, y, PLAYER_WIDTH, PLAYER_HEIGHT);
}

}