The book relies on examples to make their point, but few examples are illustrated in the book. It relies rely on the included CD for source code. If you don't see the source, you won't understand the book.

If that wasn't bad enough, the examples require the Sun Application server to see the code and behavior. I've been muscling the examples into Eclipse and Tomcat to view, which works, but it has been a big hassle when I really want to learn the concepts. It is a barrier to learning and frustrating when the book depends on the examples to communicate the concepts. It takes too long this way.

You won't like this book if you need the code samples for comprehension (you will).
You won't like this book unless you are already familiar with the Sun App Server.
You won't like this book if you are looking for a reference source when you are through.
You won't like this book unless you want a high level overview of EVERY J2EE technology in 1500 pages, including XML, DOM, XSLT, JAX-RPC, SOAP, Servlets, JSP pages, JSP documents, tag libraries, JSF, Internationaliztion, Beans, Connections, and JMS.

J2EE Connector Architecture (controversially abbreviated as JCA) is arguably one among the best JSRs created at JCP. This JSR defines a standard plug ability architecture using which various Enterprise Information Systems (EIS) can be integrated into a J2EE server. An EIS can be thought of as any resource that is outside a J2EE app, and that begs to be integrated into the larger architecture of the platform. Example: Legacy apps, SAP, mainframe apps etc...

There could be various ways to achieve this feat. Some are given below...
1. Use an EAI product; (think TIBCO) - Do u really want to enter the proprietary world of integration; my best wishes...
2. Use Messaging Servers; (think MQ Series) - Again proprietary. Ok, JMS might make it portable, but that again is just JCA in disguise. If you are wondering what I mean by that, trust me this book will clarify it.
3. Use ad-hoc integration - Use RMI, JNI, CORBA, FTP or other techniques to use the EIS API directly from your application

There are the 4th and 5th techniques too, 4th being the second best and 5th being the best up until today.
4. Use JCA
5. Use Web Services

Web Services, is an open standard that can be used by any platform for integrating other systems. But, it is still in its early phases, though it is going to be the best way to integrate enterprises going forward.

Today, JCA remains to be the most elegant architecture to solve this problem, very similar to web services, difference being that JCA is very mature, easy but only for the java platform.

During the time, I am writing this review, JCA is in version 1.5. But, when this book was written JCA was in 1.0 final and version 1.5 was proposed. So, this book is by-and-large about 1.0 version of JCA, but the author also adds some salient features that are planned for 1.5 (he calls it version 2.0, for some odd reason).

The 1.5 version of JCA has a lot of additions and improvement over 1.0 version. So, either this book needs an update for version 1.5, or you are better off typing in "112" in the "jcp.org" site and downloading the latest 1.5 specification. Trust me, this specification is well written, so you might not find it a daunting task to read it, at least not as daunting as the SOAP Note from W3C.

Or, if you are like me, read this book first, then get into the 1.5 version immediately after the basics are clear. It will be far easier to read the spec then. Choice is yours. But, do yourself a favor and keep yourself updated on JCA. It is arguably the most elegant and mature way to solve integration problems at present in the J2EE platform.

J2EE is such a mess that it's not surprising it's hard
to describe, but this book is full of forward references,
vague terminology, and non-definitive definitions.
For example, one page 491,

"The Web container evaluates a variable that appears in an
expression by looking up its value according to the behavior
of PageContext.findAttribute(String)".


This sentence leaves open the following questions:

1. Are you telling me to examine the source code of findAttribute to see what it does?

2. What, precisely, is the behavior of PageContext.findAttribute(String)?

3. What's the "String" for?

4. Aha, that's the variable's name!

5. Why is the function called findAttribute and not findVariable? Are the terms "variable" and "attribute" exact synonyms? If so, why confuse the reader. On the previous page, the book refers to a "custom tag attribute". Is that the same kind of attribute (or variable)?

Every page is full of similar minefields.

Imagine if the C Language Reference manual included the sentence:
Expressions in C are parsed according to the behavior of
"parse_expression".

I was only interested in the first part of the title, J2EE Connector Architecture. It really did not cover J2EE Connector Architecture that well and the coverage was very small. As far as the rest of the book, well, your mileage will vary. This book is probably better for a person that is new to java.

I red this book. It is excellent one for people who start learing J2EE. There are two applications are used in this book either using ejb+jsp or webservices+jsp so you can read according to what you would like to learn if you want the topic ejb+jsp so you read chapters(1,2,3,11-16,30-34,36) and if you would like to learn webservices+jsp so you have to read the chapters (1-21).