Thanks everyone in the Java ranch. Actually i have never coded in java. I have some small experience with C++ some 5 yrs ago. In my company they were compelling me to take the certification. But i wanted not to spend much time in reading books and to clear the certification fastly. The work is also hectic in my case. So the only source of my knowledge is Java ranch and its redirections, where contents are available free. Once again thanks everybody for their passive contribution in my success.