关于BufferedImage的一个问题

使用第一个可以运行，使用第二个却会报错，

Exception in thread "main" java.lang.IllegalArgumentException: input == null!
at java.desktop/javax.imageio.ImageIO.read(ImageIO.java:1400)
at Game.input.getImg(input.java:14)
at Game.GamePanel.(GamePanel.java:12)
at Game.Main.main(Main.java:10)

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.image.BufferedImage;
import java.io.FileInputStream;
import java.io.IOException;

public class input {
    public static BufferedImage getImg(String path){
        BufferedImage img = null;
                try {
              这里    img = ImagIO.read(new FileInputStream(path));
                    //img = ImageIO.read(input.class.getResource(path));

            return img;
        } catch (IOException e) {
            e.printStackTrace();
            JOptionPane.showConfirmDialog(null,"图片"+ path + "无法加载");
        }
        return null;
    }
}

input.class.getResource(path)，改为。
new ClassPathResource(path).getInputStream();path只能写文件名称。