To help make your purchasing decision easier, take a look at these great Java certification books.
1. Head First Servlets and JSP: Passing the Sun Certified Web Component Developer
Written with a style that is easy to understand and takes advantage of excellent real-world examples, this study guide is a great pick. Other books in the Head First series are equally well written and highly recommended.
2. Sun Certified Web Services Developer For Java Study Guide
This study guide offers a great CD with practice tests and labs in addition to the text. A focus on the more difficult areas on the exam is very helpful and the sometimes humorous writing keeps tough subjects understandable.3. Sun Certified Programmer & Developer for Java 2 Study Guide
If you were to pick the perfect person to write a study guide, it would logically be the person who wrote the exam, right? Well, then here is the perfect study guide because it is written by one of the developers of the exam. This book is an excellent study guide that will be useful to beginners and experts alike. The writing is converstaional and the depth of coverage is perfect.4. A Programmer's Guide to Java Certification: A Comprehesive Primer
If you are not a fan of the more light-hearted writing style and want a very in-depth study guide, this is the book for you. The author does a good job of not just covering, but really digging into the topics needed for the exam. You will be a better programmer when you are done reading this.5. SCBCD Exam Study Kit : Java Business Component Developer Certification for EJB
If you are already an experienced programmer, then pick up this study guide to help you pass the exam. The information in this book is targeted to those who need a compact, yet comprehensive study guide. Difficult topics are explained extremely well and without unnecessary embellishment.