It's just a two-dimensional array, it's really not that difficult. If you're used to Java graphics, and use an IDE like Netbeans or Eclipse, it shouldn't be a problem. I _could_ give the link to my code, but how will handing you the solution on a plate, help you as a programmer to figure things out for yourself?
Have a go and write the code. If you get stuck, post your code here and you'll get help. Good luck!
Use an IDE. Start typing.
thanks Lisa A