Enterprise JavaBeans, 4th Edition

Reviewed by: Songmuh Jong, November 2004, send e-mail Published by: O'Reilly, go to the web site Requires: JDK 1.4 or higher, JBoss 4.0 or higher, and knowledge of JDBC and distributed objects MSRP: US$44.95, CDN$65.95, UK£31.95 This O'Reilly book gives Enterprise JavaBeans (EJB) a new boost. The book is now in its fourth edition in order to keep up with the revisions of the EJB specifications. Readers of previous editions will be surprised to find that the book has significantly increased in size due to the new section on JBoss Workbook. For the first time, this book becomes an EJB book that actually guides readers in an EJB container. This welcome change will undoubtedly attract more readers and maintain the books leadership in this technical area. The first part of this book is similar to previous editions. It starts with three chapters of overview about EJB, then goes into specific discussions of individual EJB concepts, using the same Titan Cruises examples. As in earlier editions, it discusses entity beans before session beans. CMP, BMP, message-driven beans, and transactions are clearly laid out in individual chapters. A discussion of the role of EJB in J2EE is also found in its own chapter. The other major new additions to this book are the Timer Service and the web services. Essential to the EJB concepts is the existence of a database server. This is well covered in this book. The first few EJB examples take advantage of the JBoss default database and impressively create the database tables during deployment. The Appendix shows an example of setting up Oracle connection pool with JBoss. The discussion on web services also stands out in its detailed illustration of the XML schema, namespaces, SOAP, JAX-RPC, WSDL and UDDI. The only shortcoming is that the author forgot to mention there is a dependency of the exercise on a JBoss file that is not present in the default installation. Other printing errors can be found in the errata pages from the web page (see above).

Because of the complexity of EJB, each developer can most likely assume one role in the enterprise team. Whether you are a coder for the beans, the assembler of beans, or the deployer of web applications, this book provides guidance for all the roles. The workbook provides all the deployment descriptors and ant scripts (see below). Details specific to deployment can be found in those examples and in the discussion in chapter 18.

New to this book is the more than 160 pages of JBoss Workbook. Its organization is exactly what has been implied in the name: a list of exercises with limited narration. It starts with a brief but complete description of JBoss installation, followed by the chapter after chapter of examples. The source codes can be downloaded in one bundle. Better yet, it comes with ant scripts that automate the build and deploy process. Simply type 'ant' at the command prompt for each exercise, and the EJB jar file is created and deployed to the JBoss server. This feature saves readers a lot of time.

Since this book is dealing with EJB 2.0 and 2.1 while EJB 3.0 draft has been out, it is not surprising that more revisions will be needed in the near future. JBoss has implemented some EJB 3.0 features and made them available as a plug-in. Although JBoss is an excellent server, I'd love to see discussion on other servers as well, including the Sun Application Server that comes with the J2EE JDK. Readers may also want to read books on J2EE in order to cover the full spectrum of enterprise development.

This book is a great reference and instructional text on EJB. This new edition maintains its leadership as a concise discussion of this important area. The newly added JBoss Workbook is an encouraging trend. As the author points out, this book should be read after the reader has gained experience on some of the Java technology (see the Requires section). Recommended.

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