"OCA Java SE 7 Programmer I Certification Guide" is Manning's book for developers looking to get the new entry level Java certification.
I wouldn't use this book to learn Java; I'd use it as a second Java book to get ready for this exam. (Nothing wrong with this - the book doesn't claim to teach you Java. I only mention this so you have proper expectations. I actually like when a book separates objectives between teaching from scratch or exam prep.)
The book comes with mock questions after each chapter and one full mock exam. There are also "twist in the tale" exercises sprinkled throughout the book which get you to realize how small changes to the code can change the behavior of the code.
The explanations are clear. Analogies prevent you from getting bored. There are great diagrams throughout the book.
Overall, I think the best test of a cert book is whether it prepares you for the test - this book does.
Disclosure: I will be receiving a copy of this book from the publisher in exchange for being the technical proofreader for the book and for writing the forward.
Already a Certified Java Programmer (OCPJP), I used this book as a refresher before I studied for my Java 7 upgrade. The book reminded me the basic concepts like the "protected" access modifier or method overloading and overriding, things a programmer uses without realizing it.
Gupta described the topics very logically making it easy to understand and follow. There are 2 things I really liked about the book. The first is the cartoon graphics showing the humor side of the code in discussion (for example try-catch-finally). Another is the Twist in the Tale exercises enabling the reader like myself to stop and think how one minor change can affect the consequence or output of the code.
Since I used this book as a refresher, but to any OCAJP7 aspirants I recommend using this book as their study guide. It has lots of sample code and detailed explanations to questions. Exam objectives are carefully discussed in the correct chapter.
At the end, I didn't feel reading a "study guide" but actually it is.