Exception in thread "main" com.sun.j3d.utils.image.ImageException

Question

Hi I have found some code about 3d game but really I can not get why it throws such an exception please help me thanks

Exception in thread "main" com.sun.j3d.utils.image.ImageException: `javax.imageio.IIOException: Can't read input file!`
    at com.sun.j3d.utils.image.TextureLoader$1.run(TextureLoader.java:344)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.j3d.utils.image.TextureLoader.<init>(TextureLoader.java:337)
    at com.sun.j3d.utils.image.TextureLoader.<init>(TextureLoader.java:291)
    at javaapplication16.Grabbers.loadTexture(Grabbers.java:116)
    at javaapplication16.Grabbers.<init>(Grabbers.java:99)
    at javaapplication16.WrapArms3D.addGrabbers(WrapArms3D.java:162)
    at javaapplication16.WrapArms3D.createSceneGraph(WrapArms3D.java:82)
    at javaapplication16.WrapArms3D.<init>(WrapArms3D.java:64)
    at javaapplication16.Arms3D.<init>(Arms3D.java:28)
    at javaapplication16.Arms3D.main(Arms3D.java:41)
Caused by: javax.imageio.IIOException: Can't read input file!
    at javax.imageio.ImageIO.read(ImageIO.java:1275)
    at com.sun.j3d.utils.image.TextureLoader$1.run(TextureLoader.java:342)
    ... 10 more

THESE are the lines that caused the program to throws exception:

  TextureLoader texLoader = new TextureLoader(fn, null);
  Texture2D tex = loadTexture(TEX_FNM);  // used by both grabbers
  Grabbers grabbers = new Grabbers( new Vector3f(0,0,3), 1.0f);  
  addGrabbers(); 
  createSceneGraph();
  WrapArms3D w3d = new WrapArms3D();   
  { new Arms3D(); }