如何为JFrame创建单独的线程

Question

这部分代码来自我制作的动画类。它应该能够在一个单独的线程上运行动画，以免干扰我的程序的其他部分。该类扩展了Applet并实现了Runnable。

            public void paint(Graphics g)
            {
                super.paint(g);
                Graphics2D screen2D = (Graphics2D) g;
                screen2D.drawImage(sprites[currentIndex].getImage(), x, y, null);
            }

            /**
             * Will go through sprites and display the images
             */
            public void run()
            {
                int currentIndex = 0;
                while (playing)
                {
                    if (currentIndex > sprites.length - 1)
                    {
                        currentIndex = 0;
                    }
                    try
                    {
                        repaint();
                        animateThread.sleep(speed);
                    }
                    catch (InterruptedException e)
                    {
                        e.printStackTrace();
                    }

                    currentIndex++;
                }
            }

            /**
             * Will update the x and y so the images are drawn in the same location as the entity
             */
            public void update(int newX, int newY)
            {
                this.x = newX;
                this.y = newY;
            }

            /**
             * Starts a new thread to play the animation on
             */
            public void start()
            {
                playing = true;
                //animateThread = (new Thread(() -> run()));
                animateThread = new Thread(this);
                animateThread.start();
            }

下面的类是JFrame所在的位置，是制作和启动动画类的实例的地方。我没有收到任何错误，但JFrame窗口中没有显示任何错误。

public class AnimationTester extends Canvas
{
    public JFrame frame;
    private boolean running = false;
    private Animation animation;

    public AnimationTester()
    {
        Dimension size = new Dimension(400, 350);
        //setPreferredSize is in the canvas class
        setPreferredSize(size);
        frame = new JFrame();
    }

    public static void main(String[] args)
    {
        AnimationTester tester = new AnimationTester();
        tester.frame.setResizable(false);
        tester.frame.setTitle("Tester");
        tester.frame.add(tester);
        tester.frame.pack();

        tester.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        tester.frame.setLocationRelativeTo(null);
        tester.frame.setVisible(true);

        //Make the window not have to be clicked on to get input (Set is as the main focus when it begins)
        tester.requestFocusInWindow();

        //Start the program
        tester.start();
    }

    public void start()
    {
        try
        {
            animation = new Animation(ImageIO.read(getClass().getResource("/SpriteSheet.jpg")), 16, 2, 200, 250, 250, 2.0);
            animation.start();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }


    }

}