This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I do not mean to sound rude or anything, but I have been noticing you are posting a lot of "what is..." and "how to..." type questions. Of course this would mean you are very keen on learning new stuff. However it might be a good idea to read http://faq.javaranch.com/java/SearchFirst