Although this book is a good review for the certification exam, it is filled with errors in code and language. Many code examples, when applied into JDK, gave results that were different than expected (compile errors etc.). Computer programming textbooks, especially a study guide for certification, cannot afford to be sloppy.
I am not a publisher and do not claim to know anything about publishing. However, I was taken aback by the lack of attention given to the correctness and compilibility of the code examples. I would compare it to missing ingredients in a book of recipes. It might be excusacble as an oversight or typo - but what good is it to you if you have to keep second-guessing the contents.
Do not attempt to take the certification exam with this book as your only source (unless you are a Java Guru and a walking Java compiler). The most helpful book I have found is Deitel & Deitel's Java How to Program Third Edition. All of their code compiles cleanly and they give wonderful explanations of the topics at hand.
You can buy The Complete Java 2 Certification Study Guide, by Simon Roberts, Philip Heller and Michael Ernest (although this book has many errors and is bone dry when it comes to real life analogies and examples) and use the Exam Notes review as a review only!! There is a lot that is mentioned in the review book that is not covered in the Study Guide and vice versa.
I am a computer professional for close to ten years and am relatively new to Java. I was able to get Sun Certified only through mixing and matching the strengths of many Java books and web resources.
I still think it's worth your time to get the review book - but just be aware that it does not come without its shortcomings.
Good luck to all you certification candidates!! The exam is tough!!