Sanjit Roy reviews XML and Web Services Unleashed (Bloomberg, Darby, et al, Sams Publishing, paperback, $49,99):

When I received my copy of this book, I was eager to read it after examining the table of contents. It covered almost every topic one could think of related to XML! I have quite a few books on XML and J2EE programming, but none covered as broad a spectrum of XML technologies as this one. However, because the authors tried to cover such a broad range, the book takes an introductory or "survey" approach to the subject matter. The book is well structured in spite of having nine authors. It's divided into four parts. The first part covers the fundamentals of XML and their validation using DTDs and schemas. These two topics are covered in about 100 pages. The authors provide many examples on schemas, which are assumed to be self-explanatory. A brief review of XPath, XPointer, and XLink is grouped into a separate chapter. Another chapter is dedicated to alternate schema representations using XDR, DSD, DCD, and Schematron. These are referred to as "dead" formats, but the chapter gives you an idea of the various other schema formats proposed, including the object-oriented SOX.

The second part (the best part!) focuses on building XML-based applications. XML parsing using DOM, JAXP, JDOM, and JAXB are covered in the same chapter. Some of the new features of DOM Level 2 specification are described briefly, including DOM traversal and range. XML parsing using SAX 2.0 is covered in the subsequent chapter. The sample code is written in Java using the Xerces parser. One interesting chapter focuses on XML transformation into XML/HTML using style sheets. Sample codes illustrate basic XSLT processing using MSXML Parser 3.0 and Apache Xalan API. The interesting part is the section on XSL Formatting Objects (XSL-FO), which lets you transform XML documents into PDF documents. The chapter on integrating XML with data is very generic, as different database vendors have proprietary XML implementations.

The book did not live up to its title for coverage of the various Web services topics, which are covered in three chapters. The first chapter introduces Web services and outlines its basic architecture. The description of the SOAP specification is very theoretical. The coverage of the basic SOAP syntax, envelopes, and header was adequate. However, the SOAP body element could have used more details. It would have been nice if the authors had written detailed examples of Web services and clients using both Microsoft and the Apache SOAP APIs. Also, the examples cover RPC-style Web services and miss out on the message-oriented Web services architecture. WSDL and UDDI are covered in a single chapter that mainly discusses the architectural issues, and there's brief coverage of the Microsoft SOAP Toolkit and the IBM Web Services Toolkit. The UDDI section covers the architecture and demonstrates the two competing vendor implementations - IBM's UDDI4J and Microsoft's UDDI SDK. There are two chapters dedicated to XML implementation models using the .NET framework using ADO.NET and Visual Studio .NET.

The third part of the book discusses various topics on implementing XML in e-business and B2B integration. These chapters expose the reader to many of the talked-about technologies, like the CommerceNet eCo Framework, XML/EDI, ebXML, and RosettaNet. Topics are covered briefly and their implementation models are discussed. There's limited coverage on delivering wireless and VoiceXML services in a separate chapter. The authors provide brief discussion of WML/VoiceXML concepts and their respective structures and elements. These topics are only introductory, and any reader developing these types of applications would probably need to refer to other materials.

The final part covers semantic Web topics. The main focus is on Resource Description Framework (RDF) and its specifications, working drafts and notes, data model, and schema. Conclusion
Overall, all XML developers would like to have this book on their desks as an introductory reference to many XML-related technologies and topics. The book does not contain a CD-ROM; however, the source code for the examples can be downloaded from the publisher's Web site.

I must admit that this book isn't for the beginner. It assumes the reader has some fundamental knowledge of XML and Java programming and exposes the reader to the XML technologies that are currently available. The book does not delve very deep into any particular topic, but rather provides enough information to get the reader started.

This book is ideal for an experienced developer or architect who has started working with XML and wants to quickly cover the entire XML landscape.