It shows empty frame.

[WaleedMortaja]

I copied the two source files (Game, Sprite) to NetBeans , copied assets folder to the folder of the project containing the source files, run the file and the get error

Exception

in thread "Thread-2" java.lang.IllegalArgumentException: input == null! at javax.imageio.ImageIO.read(ImageIO.java:1388) at javaapplication21.Game.getSprite(Game.java:89) at javaapplication21.Game.init(Game.java:56) at javaapplication21.Game.run(Game.java:44) at java.lang.Thread.run(Thread.java:745)

As I understood that threat doesn't need to take argument. so, I deleted "this" argument. The error doesn't appear again. But still have an empty frame ( before and after deleting "this" argument) Is my way of running the code wrong ? Can you help me trying this, please?