I have learned the sun Java Tutorial.But I would like to study more.
If you already went through the tutorial, going through more books may help, but IMHO, it will probably be boring. I recommend using what you learned.
Do you have a hobby? Like certain puzzles? Found certain math problems interesting? Then, I suggest actually writing a program, that is bigger than those sample programs that you see in books. Write a program that is related to your hobby -- something that you would be interested in using.
Henry