Java - ImageIO没有得到图片

Question

我正在尝试将图像sprite_sheet.png添加到我的游戏项目中，但是我收到了这些错误：

Exception in thread "main" java.lang.IllegalArgumentException: input == null!
at javax.imageio.ImageIO.read(Unknown Source)
at az.rehman.gfx.SpriteSheet.<init>(SpriteSheet.java:16)
at az.rehman.game.Game.<init>(Game.java:29)
at az.rehman.game.Game.main(Game.java:127)

以下是我的课程：

package az.rehman.gfx;

import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
public class SpriteSheet {
public String path;
public int width;
public int height;

public int[] pixels;

public  SpriteSheet(String path) {
    BufferedImage image = null;
    try {
        image = ImageIO.read(SpriteSheet.class.getResource(path));
    } catch (IOException e) {
        System.out.println("SpriteSheet file exception");
        e.printStackTrace();
    }

    if(image == null)
        return;

    this.path = path;
    this.width = image.getWidth();
    this.height = image.getHeight();

    pixels = image.getRGB(0, 0, width, height, null, 0, width);

    for(int i = 0; i < pixels.length; i++) {
        pixels[i] = (pixels[i] & 0xff/64);
    }

    for(int i = 0; i < 8; i++) {
        System.out.println(pixels[i]);

    }


    } // constructer end




} // class end








package az.rehman.game;

import az.rehman.gfx.SpriteSheet;

import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import javax.swing.JFrame;

public class Game extends Canvas implements Runnable {

public static final long serialVersionUID = 1L;

public static final int WIDTH = 160;
public static final int HEIGHT = WIDTH / 12 * 9;
public static final int SCALE = 3;
public static final String NAME = "Game";

private JFrame frame;

public boolean running = false;
public int tickCount = 0;

private BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
private int[] pixels = ((DataBufferInt) image.getRaster().getDataBuffer()).getData();

private SpriteSheet spriteSheet = new SpriteSheet("\\sprite_sheet.png");

public Game() {
    setMinimumSize(new Dimension(WIDTH * SCALE, HEIGHT * SCALE));
    setMaximumSize(new Dimension(WIDTH * SCALE, HEIGHT * SCALE));
    setPreferredSize(new Dimension(WIDTH * SCALE, HEIGHT * SCALE));

    frame = new JFrame(NAME);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLayout(new BorderLayout());
    frame.add(this, BorderLayout.CENTER);
    frame.pack();
    frame.setResizable(false);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
}

public synchronized void start() {
    running = true;
    new Thread(this).start();
}

public synchronized void stop() {
    running = false;
}


public void run() {
    long lastTime = System.nanoTime();
    double nsPerTick = 1000000000D / 60D;

    int ticks = 0;
    int frames = 0;

    long lastTimer = System.currentTimeMillis();
    double delta = 0;


    while (running) {
        long now = System.nanoTime();
        delta += (now - lastTime) / nsPerTick;
        lastTime = now;
        boolean shouldRender = true;
        while (delta >= 1) {
            ticks++;
            tick();
            delta -= 1;
            shouldRender = true;
        }

        try {
            Thread.sleep(2);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        if (shouldRender) {
            frames++;
            render();
        }

        if (System.currentTimeMillis() - lastTimer >= 1000) {
            lastTimer += 1000;
            System.out.println(ticks + " ticks, " + frames + " frames");
            frames = 0;
            ticks = 0;
        }

    }


}

public void tick() {
    tickCount++;

    for (int i = 0; i < pixels.length; i++) {
        pixels[i] = i + tickCount;
    }


}

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

    g.drawImage(image, 0, 0, getWidth(), getHeight(), null);
    g.dispose();
    bs.show();
}

public static void main(String[] args) {

    new Game().start();
}

}