This book was written in 2006 and is targeting client side developers who want to add Ajax to their Java backed applications. The book tends to cater more towards an audience who likely wants an overview of various Ajax frameworks out there in order to get their feet wet or make a decision on which one to go with. The book does a good job by starting out with coverage of thee basic principles of Ajax and debugging tools etc. It then goes into specific Ajax frameworks, specifically Prototype, Scriptaculous, Dojo and Taconite. Sorry no JQuery here, when this book was written it was likely too new. The book then goes on to cover DWR with its own dedicated chapter. Towards the middle of the book the authors take a turn and focus more on Ajax integration with two Java front end frameworks, specifically Struts 1 and Tapestry. Finally the authors wrap up with Spring and JSF coverage. The latter two topics seemed a bit out of place.
Recommended? Skip it, the book is outdated by now. If you are unfamiliar with Java/Ajax integration and can get this book for under $10, you might consider it.
Skill levels: Beginner to Intermediate. Folks evaluating various frameworks and want an Ajax overview.