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Rating: 
Summary: Good book for jumping in
Review: All you need to jump in, for more details go for 'Special Edition Using Enterprise JavaBeans 2.0', rare case when O'Reilly's book is not a head above the rest. 'Special edition' is deepier and a better choice for advanced programmers.
Rating:
Summary: Recommended
Review: This book gives an excellent overview of Enterprise JavaBeans and their applications. At all times the author does an effective job of relating to the reader the concepts behind this new methodology. Even performance issues involved with the utilization of Enterprise JavaBeans is discussed briefly in the book and both versions 1.0 and 1.1 are covered. The reader is expected to be an expert in the Java programming language, and have familiarity with the JDBC API or SQL. The author begins Chapter 1 with an introduction to distributed objects, server-side components, and component transaction monitors (application servers). Enterprise JavaBeans is defined as a server-side component model for component transaction monitors. The standard 3-tier architecture is illustrated, along with definitions of stub and skeleton, and the RMI protocol. Effective diagrams and Java source code are used to describe the distributed object model. The chapter ends with a defense of using server-side components and the author employs an imaginary business application as an illustration of the concepts. This example is expanded upon throughout the rest of the book. The architecture of EJB is covered in Chapter 2, with entity beans and session beans the two main components. The author carefully distinguishes between these two bean types. The remote interface, the home interface, the bean class, and the primary key are all described in detail and the author shows how to build a bean with relevant Java code. Deployment descriptors, which enable customization of software behavior at runtime, and JAR files, used for packaging Java classes, are both treated in detail. The author is careful also to distinguish the differences between 1.0 and 1.1. The resource management capability of component transaction monitors are discussed in the next chapter. Application performance is critically dependent on this capability, and the author stresses the benefits of using EJB servers to meet the heavy load requirements while still maintaining optimum performance. State transition diagrams are effectively employed to explain instance swapping, the activation mechanism, concurrency, and persistence of beans. Security of EJB is also discussed with authentication, access control, and secure communication being supported. In the next chapter the example business application is used to guide the reader through the actual development of an entity bean and a session bean. Again, two different versions of the beans are developed, depending on whether 1.0 or 1.1 is used. JNDI is used in the next chapter to give an overview of beans from the clients perspective, and allows the application to view the EJB server as a collection of directories. After locating and obtaining the remote reference to the EJB home using JDNI, a remote reference to the bean can then be obtained. State transition diagrams are again employed to illustrate the Java RMI serialization and remote reference. The author returns to a more detailed discussion of entity beans in Chapter 6. He outlines the advantages of using entity beans instead of accessing the database directly. Container-managed and bean-managed persistence are thoroughly treated, and the author shows how Create methods come into play for both of these beans. A nice state transition diagram is given for the life cycle of an entity bean along with a detailed description on what causes transitions among the different states. Session beans are then the topic of Chapter 7, and the author discusses when to use session beans versus entity beans. In addition, the other properties of session beans are discussed and the lifecycles of both a stateless session bean and a stateful session are given in terms of state transition diagrams. Transactions are discussed in the next chapter, with the concept of declarative transaction management discussed, which allows the transactional behavior to be controlled using the deployment descriptor. The author details the advantages of employing declarative transaction management. Effective diagrams are employed to illustrate transaction attributes. In addition, isolation and database locking is discussed in detail along with explicit transaction management. The later is used with the Java Transaction API used by EJB to deal explicitly with transactions. A very useful state transition diagram is given for the transactional stateful session bean. The next two chapters are written from a design perspective, and discuss how to solve particular design problems, working with specific databases, and XML deployment descriptors. These chapters are specialized discussions and are geared toward those who are actually involved in the designing and coding of EJB applications. The author does address how to improve performance with session beans, treating in particular the network traffic and latency issues, and resource consumption. Method calls on a remote reference will initiate a remote method invocation loop, which will send streamed data from the stub to the server and then back to the stub, and thus consume bandwidth. Network traffic will mushroom as more clients create more beans, update their states, and request information. Reducing the EJB network traffic is a challenge to the application developer and many proposals have been given on the Web and in the literature for how to best do this. Network modelers have to pay particular attention to these issues when EJB is being deployed in an application to be run over a network. The last chapter covers the J2EE with discussions of servlets, application client components, and connectivity. There are very useful appendices inserted at the end, especially Appendix B, which gives the state and sequence UML diagrams for all of the bean types discussed in the book. Appendix D is also useful since it discusses the new features available in EJB 1.1.
Rating: 
Summary: Excellent Book for new and intermediate EJB developers
Review: This book is aim at Java developers wishing to learn the fundamentals of Enterprise Javabeans.
Knowledge of Java and JDBC is assumed. If you ask to any EJB developer which are the best books about EJB, many will respond with two;
Mastering EJB (Ed Roman) and this one. Mastering EJB also covered JDBC, RMI and other topics.
The 1st and 2nd editions of Enterprise Javabeans (Richard Monson-Haefel, Orielly) focus specifically on
understanding and using EJB. Both are very good and worth reading. The book is made up of 17 chapters, covering the all basics, intermediate topics and some advanced.
The first chapter introduces distributed object architectures and component models.
This chapter gives the reader an understanding of RMI and CORBA, the technologies that EJB was originally built on. Chapters 2 and 3 present the EJB architecture and the main services provided by the architecture.
These chapters are very important to read because they cover essentially what is an EJB,
the advantages of EJB and a few differences between EJB 1.1 and EJB 2.0.
If you have read either of the previous two editions, you will like the EJB 2.0 specifics
(e.g. Message Driven Beans) introduced in these chapters. A TravelAgent EJB is used as an example through out chapters 2 and 3. Chapter 4 gives the reader their first introduction to EJB source code.
We recommend you download the workbook and source code examples (...)
Currently only Web Logic 6.1 and Web Sphere 4.0 versions are available. Chapter 5 present Session and Entity beans with a quick overview of JNDI and Java RMI-IIOP.
The chapter focuses on the Remote and Local (EJB 2.0) client APIs.
The author also shows how to redesign an EJB to use a Local Interface instead of a Remote interface.
What we really like are the code snippets used to demonstrate the theory.
Chapters 6 and 7 go into detail about Entity Beans (CMP 2.0).
Chapter 8 covers EJB QL, similar to SQL but designed to work with the abstract persistence schema of EJB 2.0 Entity Beans.
Again, there are lots of code examples and helpful class diagrams.
Chapter 9 provides a useful guide to differences between CMP in EJB 1.1 and EJB 2.0.
Chapter 10 and 11 describe BMP and Entity-Container contracts (primary key class).
These are explained quite clearly considering these are not simple topics.
Chapter 12 focuses on explaining Stateless and Stateful Session Beans. Chapter 13 presents Message-Driven Beans. After an overview of JMS, a ReservationProcessor EJB is described.
This chapter shows sending messages between client and message bean.
Chapter 14 covers transactions with some example EJB code. In chapter 15, the author gives some design strategies that should be followed.
These include passing objects by value and implementing a common interface.
Chapter 16 is all about XML deployment descriptors. The last chapter (17) gives an idea of what to expect in future releases. There has been alot added to this book since the previous editions. We recommend this book to all developers that would like
to learn about EJB step by step. It would have been nice to have more EJB Design Patterns, however, there is enough in this book
to keep most developers happy. Go buy it now!
Rating:
Summary: Best info on the EJB 2.0 specification
Review: This is the third edition of "Enterprise JavaBeans" in three years, which shows how popular this book is and how fast EJB technology is changing. This new edition has been updated for EJB 2.0 and it gives excellent coverage to the many changes in the new specification. Some of the changes covered include message-driven beans, the new CMP model for entity beans, the EJB Query Language, and how to build complex relationships between entity beans. The book is written for the advanced Java developer who wants to learn the complexities of Enterprise JavaBeans. This is not a simple tutorial for the beginner. The book starts with a brief introduction to EJB and then spends the next couple of chapters covering the complexities of the EJB architecture. After a brief review of the basics of EJB, the author spends the next three chapters covering the complexities of EJB 2.0 container managed persistence. Bean-Managed persistence and the entity-container contract are then covered followed by a chapter on session beans. The new message-driven beans are given a chapter. The book ends up with a chapter on design considerations for J2EE applications. The author does an excellent job of including diagrams at just the right places to help clarify difficult topics. Anyone who will be working with EJB 2.0 should own this book. Note: Companion workbooks are available from the O'Reilly website. These include instructions and versions of the sample programs for WebLogic and WebSphere.
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