Seems like you want to program to hack? ffs...
If you really want to be like this, just go on and get c++...
I have learnt Java and its not used for hacking as far as I am concerned, I have done a reasonable amount of research to tell you that Java is more focused on software engineering rather than hacking. If you want to try for viruses and things related to it, have a look at batch programming, if not your only choice shall be c++.
---------- Post added at 05:38 PM ---------- Previous post was at 05:29 PM ----------
Hackers exist in mainly these languages: C, C++, Perl, Python, PHP, BASH, Java's main use on the client side is to create applets, small programs that download over the internet and run inside web browsers. Java allows you to play online games, chat with people around the world, calculate your mortgage interest, and view images in 3D, just to name a few. It's also integral to the intranet applications and other e-business solutions that are the foundation of corporate computing. As you can see Java has other uses.