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Reviewer: Satadip Dutta

Java 2 Enterprise Edition (J2EE) is a constantly evolving set of technologies that provides a framework to easily develop distributed applications in Java. This book provides a quick introduction to various technologies in the J2EE stack; the chapters are rich with source code and examples. The 1,500-page book focuses on four main areas: Extensible Markup Language (XML)-related technology for developing Web services, Web tier technology for developing the presentation layer, Enterprise JavaBeans (EJB) tier technology for developing business logic, and platform services available to any J2EE application. Application programming interfaces (APIs) for XML processing were introduced in J2EE 1.4 to support the development of Web services applications. The chapters in this section introduce the basics of XML, and how they can be parsed using Simple API for XML (SAX) and the document object model (DOM). The authors introduce the Java API for XML-Remote Procedure Calls (JAX-RPC), which allows clients to execute procedures on remote systems using simple object access protocol (SOAP). This chapter describes both static and dynamic proxy clients. SOAP with attachments API for Java (SAAJ) is covered, with excellent illustrations of SOAP messages. The authors walk users through the various scenarios of creating and sending SOAP messages. A key part of Web services is to have the ability to query a registry to find available services. Java APIs for XML Registries (JAXRs) provide a common way to access different types of XML registries; these are also covered. The next set of technologies deal with the presentation layer. These chapters cover technologies like JavaServer Pages (JSP), servlets, internationalization, and the new JavaServer Faces (JSF) and JSP standard tag library (JSTL). Apart from explaining the basics of JSP and servlets, the authors justifiably devote three chapters to JSF, a new addition to J2EE 1.4. JSF provides a standard framework for representing user interface (UI) components, state information, event handling, and so on, to enable a clean separation between the presentation and the behavioral logic. JSF also supports the creation of custom UI components. The chapter on JSTL covers only the commonly used tag library, for example, flow controls, internationalization, structured query language (SQL), and so on. However, the overall coverage of these tags does provide a good foundation, which can be used to learn other tag libraries that are not covered. The chapters on EJB technologies cover the usual set of technologies, like session beans, entity beans, message driven beans, and EJB query language. A sample application (available on the companion CD) is used as the underlying example, to introduce the various concepts. These chapters contain a basic introduction to concepts pertaining to session and entity beans. They are further illustrated with examples of container managed persistence, and bean managed persistence, for entity beans. The chapters on J2EE services touch upon transactions, resource connections, databases, mail, security, and Java Message Service (JMS). JMS can be used to process both asynchronous and synchronous messages, in conjunction with message-driven beans. The book devotes two chapters to this topic, and provides very good examples. The book comes with a companion CD, and a Web site that contains an online version of the book, and the associated examples. The application server used for all of the examples is the Sun Application Server Platform 8. There are two chapters dedicated to explaining end-to-end sample applications. The book could be improved. The structure of the chapters varies greatly, and makes the book seem like a compilation of a bunch of chapters written by different authors. The text tries to cover a lot, and, in doing so, briefly touches on the basics only. It would have been nice to see some quick tips on usage and pitfalls, which would encourage users to explore design decisions appropriate for these technologies. Also, given that the specifications for the various technologies in the J2EE stack change constantly, it would have been nice to see the changes between 1.3 and 1.4 summarized briefly at the end of each chapter. Overall, I think this is a good book for readers who want to get a quick idea about the various technologies available in J2EE 1.4. This book would be a good reference; the chapters can be read out of order, and the information in the book is sufficient to start a deeper investigation into selected J2EE technologies, using other resources. There is an online version of this book available at http://java.sun.com/docs/books that readers may want to peruse before buying the printed book. Beginners, managers, and students will find this book useful for getting a basic understanding of J2EE technologies. Online Computing Reviews Service