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.
Is it because of explicit declare of constructor with parameter argument in super class will need to declare constructor with no argument as well?
Exactely. The compiler only automagicaly inserts a non argument constructor in a class when no other constructor is present. And sub class constructors without a explicity call to a super class constructor will have a call to a non argument super class constructor automagicaly inserted