Hi Abhay,
Good question. There are many pattern books available, some are seminal works such as the original GoF book that are generic, others are written for a specific language. In our case we wrote with
Java EE in mind. We have taken traditional GoF patterns and shown how they are implemented in Java EE using the special features of Java EE such as CDI. In addition to discussion about the implementation in Java SE and Java EE, and many code examples we also tell a story of a situation where the pattern saved the day or caused more problems than it solved. In short, what is different is that we related known design patterns directly to Java EE.
Thanks Alex