Illegal Argument Exception for loading image

问题

I'm currently programming a game and trying to load and image from an ImageLoader class and I keep receiving this error:

Exception in thread "main" java.lang.IllegalArgumentException: input == null!
at javax.imageio.ImageIO.read(ImageIO.java:1338)
at game.ImageLoader.getImage(ImageLoader.java:24)
at game.TestPanel.<init>(TestPanel.java:38)
at game.TestApplication.main(TestApplication.java:26)

Here is the code to my class that's calling the ImageLoader class, yet I also receive an error on my catch block:

    public TestPanel ()
        {
        try
        {
            ClassLoader myLoader = this.getClass().getClassLoader();
            ImageLoader loader = new ImageLoader();
            backdrop = loader.getImage("resources/Asteroid.jpg");
            ImageLoader test = new ImageLoader();
            ship = test.getImage("resources/Alien-Ship.png");
            InputStream pointStream = myLoader.getResourceAsStream("resources/path_1.txt");
            Scanner s = new Scanner (pointStream);
            objectPath = new PathPoints(s);
            squid = objectPath.getStart();


        }
        catch (IOException e)
        {
            System.out.println ("Could not load: " + e);
        }
        addMouseListener(this);
    }

And here is the code for my ImageLoader class:

    import java.awt.Image;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.Scanner;

    import javax.imageio.ImageIO;

    public class ImageLoader {

    public Image loadedImage;

        public ImageLoader(){


        }

        public Image getImage(String s){
        try
                {
                    ClassLoader myLoader = this.getClass().getClassLoader();
                    InputStream imageStream = myLoader.getResourceAsStream(s);
                    loadedImage = ImageIO.read(imageStream);
                }
                catch (IOException e)
                {
                    System.out.println ("Could not load: " + e);
                }

                return loadedImage;
         }

        }

Why is it throwing null!, I have tried to change the path of resources/Asteroid.jpg to /resources/Asteroid.jpg yet it changed nothing.

Edit: resources relates to my classpath because it is the package in which I am storing my image and point resources in.

来源：https://stackoverflow.com/questions/15802234/illegal-argument-exception-for-loading-image