This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Siva, You wouldn't even profile every time you change code. Only if you are trying to solve a performance problem or gather statistics. It's good to get working code before you worry about its performance.
Rebuilding a project doesn't publish to the server. Rebuilding is for compiling, publishing is for running. When in doubt, publish (or restart the EAR on the server.)