This is a very useful book with many good examples. If you are already familiar with Java it is a very good place to expand your knowledge.
I have a question though. What is a "nested class". They are used in this book quite a bit. For me, they compile fine but will not run. I have to comment out some lines to remove them. For example in Ex 2.8 the LinkedList program, I have to comment out two lines for the program to run. These two lines are:

public static class Test {

and the last

}

I have several Java books but I have never seen "nested classes" mentioned.