Adam Bien is in some places requires knowledge of the Core J2EE Patterns of D. Alur, Crupi J. and D. Malks. These are critically reviewed and updated. Many of the J2EE Patterns are cleverly into retirement. It is an ideal complement when you have been preparing for example, SCEA and already dealt intensively with the Core J2EE Patterns.
But there are not only the traditional J2EE Patterns revised and shown how they can be replaced by simpler mechanisms, but there are also new patterns introduced, arising out of new Java EE APIs.
The information density per page is high. Nevertheless, Adam Bien writes far less abstract than the authors of the Core J2EE Patterns.