我尝试下载图像，但发生错误“无法解决”

Question

我正在学习编程，所以我在上其中一门课。在上课期间，一切进展顺利，直到添加小精灵为止，我已经尝试了很多类似使用此代码的方法

我尝试使用以下代码：How do I add a resources folder to my Java project in Eclipse

这是JAVA中的完整代码：

public class Game extends Canvas implements Runnable{


    private static final long serialVersionUID = 1L;
    public static JFrame frame;
    private boolean isRunning = true;
    private Thread thread;
    private final int WIDTH = 160;
    private final int HEIGHT = 120;
    private final int SCALE = 3;
    private BufferedImage image;
    public Spritesheet sheet;
    public List<Entity> entities;
    public Game(){


        this.setPreferredSize(new Dimension(WIDTH*SCALE,HEIGHT*SCALE));
        image = new BufferedImage(WIDTH,HEIGHT, BufferedImage.TYPE_INT_RGB);
        frame = new JFrame();
        frame.add(this);
        frame.setResizable(true);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
        //iniciando objetos\\
        entities = new ArrayList<Entity>();
        sheet = new Spritesheet("/spritesheet.png");
        Player player = Player(0,0,16,16, spritesheet.getSprite(33, 0, 16,16));
    }

    public synchronized void start() {
        thread = new Thread(this);
        isRunning = true;
        thread.start();


    } 

    public synchronized void stop(){
        isRunning = false;
        try {
            thread.join();

        } catch (InterruptedException e) {

            e.printStackTrace();}



    }

    public static void main (String args[]) {
        Game game = new Game();
        game.start();

    }

    public void tick(){
        for(int i = 0; i < entities.size(); i++) {
            Entity e = entities.get(i);
            e.tick();
        }
    }

    public void render () {
        BufferStrategy bs = this.getBufferStrategy();
        if (bs == null) {
            this.createBufferStrategy(3);
            return;     
        }

        Graphics g = image.getGraphics();
        g.setColor(new Color(19,19,19,19));
        g.fillRect(0,0, WIDTH, HEIGHT);
        g = bs.getDrawGraphics();
        g.drawImage(image, 0, 0, WIDTH*12, HEIGHT*12, null);
        bs.show();
        for(int i = 0; i < entities.size(); i++) {
            Entity e = entities.get(i);
            e.render(g);
        }
    }
    public void run() {
        long lastTime = System.nanoTime();
        double amountofticks = 60.0;
        double ns = 1000000000 / amountofticks;
        double delta = 0;
        int frame = 0;
        double timer = System.currentTimeMillis();
        while(isRunning) {
            long now = System.nanoTime();
            delta+= (now - lastTime) / ns;
            lastTime = now;
            if (delta >= 1) {
                tick();
                render();
                frame++;
                delta--;
            }
        if(System.currentTimeMillis() - timer >= 1000) {

            System.out.println("FPS: " + frame);
            frame = 0;
            timer+=1000;

        }


        }

        stop();
    }
}

控制台上显示的错误：

  

线程“主”中的异常java.lang.Error：未解决的编译   问题：无法解决Spritesheet。