|Introductory books are sometimes very hit and miss as it can be challenging to find a level easy enough for the uninitiated to pick up but at the same time interesting enough to make the reader want to continue learning with more advanced material. This in general is a well executed introductory book on EJB3 with a clear structure and text convention.|
Chapter 1 offers a crash course to the JEE and EJB 3 architecture and guides the reader through the installation and configuration of the environment all code samples will be executed in. It will be useful to download the code samples from the publisher’s website as examining and running the samples reinforces the messages in the book.
Chapter 2 introduces the session bean and uses a couple of code samples to describe the client and the lifecycles of both forms of session bean.
Chapters 3 to 5 build on the various bean concepts and the author begins to create the building blocks for a conceptually simple banking application, with code organised and layered in a familiar way (using session and entity beans). This fits comfortably within the capabilities of the target audience, and holds no real surprises. Readers with some exposure to EJB3 will also get some benefit as the various strategies and alternatives around concepts are explored, thereby offering an insight into the possible options available (e.g. primary key strategies, the set of annotations that can be used etc.)
Chapters 6 and 7 look at how the container plays a part in an application’s lifecycle – the entity manager and transactions are explored. While it’s useful to have an understanding of how databases work in order to appreciate how for example the various isolation levels work, the author does take some time in order to explain the basics.
Chapters 8 and 9 look at how applications can be written to have a level of autonomous behaviour by introducing message driven beans and the Timer service.
Chapter 10 describes the interceptor, and keeps the AOP concept as easy as possible to understand by using the standard logger/timer/auditor interceptor idea.
No developer focussed book is ever complete without a look at web services and security, and this one also ticks those boxes. Over the course of two chapters, the author takes the reader through the process of setting up an EJB as a webservice endpoint and explains the structure of the WSDL document. Security matters are also explored with a basic introduction into authentication, both declarative and programmatic authorisation and also discusses container security.
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