Solutions to selected exercises can be found in the electronic document The Thinking in Java Annotated Solution Guide, available for a small fee from www.BruceEckel.com.
Create two classes, A and B, with default constructors (empty
argument lists) that announce themselves. Inherit a new class called C
from A, and create a member of class B inside C. Do not
create a constructor for C. Create an object of class C and
observe the results.
 Dont fall prey to the urge to prematurely optimize. If you get your system working and its too slow, its doubtful that you can fix it with the final keyword. However, Chapter 15 has information about profiling, which can be helpful in speeding up your program.