Input == null! ERROR?

[reuben_1]

I have this big problem with my code, here it is:
https://www.dropbox.com/s/2lc6iygbx2gwlqj/Screenshot%202014-07-19%2011.24.20.png

here is my ERROR:
Exception in thread "Thread-0" java.lang.IllegalArgumentException: input == null!
at javax.imageio.ImageIO.read(ImageIO.java:1348)
at ca.gingerninja.game.gfx.SpriteSheet.<init>(SpriteSheet.java:19)
at ca.gingerninja.game.Game.Screen(Game.java:55)
at ca.gingerninja.game.Game.run(Game.java:78)
at java.lang.Thread.run(Thread.java:745)

Can someone please help, I would really like to continue with my game!

[reuben_1]

Here if you need this:
https://www.dropbox.com/s/ebg4hc071ddie3f/Screenshot%202014-07-19%2011.27.42.png

[Kwag]

Why don't you use libgdx for game development?

[reuben_1]

what is libgdx? Does it include writing all the java codes?

[JamesCherrill]

It can't read the image file. Possibly because the file is invalid, but much more likely it's looking for it in the wrong place. Java's default folders are often a source of confusion.
To see where Java is looking for a file (eg "images/image1.jpg") you can use something like this to print the complete path where Java is looking...

System.out.println(new File("images/image1.jpg").getCanonicalPath());