Web services, the new way of stitching data and processing resources together to form elaborate, distributed applications, aren't like other software systems. They differ even from other architectures for distributed applications. In his fantastic Understanding Web Services
, Eric Newcomer helps his readers figure out what Web services are all about. This book is better than any other book out there in helping readers come to grips with the terms, technologies, behaviors, and design requirements that define the Web services universe. It's remarkably light on code--Newcomer's logic appears to be that you should dig into the details of implementation only after you thoroughly understand the design concepts--and emphasizes definition and exposition of SOAP, UDDI, WSDL, and ebXML.
Newcomer's work looks and reads almost like a notebook, with succinct statements in the margin (for instance, "SOAP processors first have to check the mustUnderstand attribute, if any"), adjacent to paragraphs that go into greater depth. He's careful to call attention to differences among the relevant standards documents, and points out differences among implementations. Graphical learners may wish for more conceptual diagrams, as there aren't a lot of them here. Newcomer's prose is brilliant, though, and it's pretty easy to determine what he means. Perhaps best of all, Newcomer isn't cheap with his opinions and forecasts. It's helpful to read his informed feelings and predictions. --David Wall
Topics covered: The specifications, implementations, and popular trends that define the Web services movement. Conceptual coverage of Extensible Markup Language (XML), Simple Object Access Protocol (SOAP), Web Services Description Language (WSDL), and the Universal Description, Discovery, and Integration (UDDI) protocol fills these pages. Emphasis is on how it all works rather than on how to program for it.
From the Back Cover
Web services enable the new generation of Internet-based applications. These services support application-to-application Internet communication--that is, applications at different network locations can be integrated to function as if they were part of a single, large software system. Examples of applications made possible by Web services include automated business transactions and direct (nonbrowser) desktop and handheld device access to reservations, stock trading, and order-tracking systems.
Several key standards have emerged that together form the foundation for Web services: XML (Extensible Markup Language), WSDL (Web Services Definition Language), SOAP (Simple Object Access Protocol), and UDDI (Universal Description, Discovery, and Integration). In addition, ebXML (Electronic Business XML) has been specified to facilitate automated business process integration among trading partners.
This book introduces the main ideas and concepts behind core and extended Web services' technologies and provides developers with a primer for each of the major technologies that have emerged in this space. In addition, Understanding Web Services summarizes the major architectural approaches to Web services, examines the role of Web services within the .NET and J2EE communities, and provides information about major product offerings from BEA, Hewlett-Packard, IBM, IONA, Microsoft, Oracle, Sun Microsystems, and others.
Key topics include:
- XML facilities for structuring and serializing data
- How WSDL maps services onto communication protocols and transports
- WSDL support for RPC-oriented and document-oriented interactions
- SOAP's required and optional elements
- Message processing and the role of intermediaries in SOAP
- UDDI data formats and APIs
- How ebXML offers an alternative to Web services that supports reliable messaging, security, and trading-partner negotiations
With Understanding Web Services , you will be well informed and well positioned to participate in this vast, emerging marketplace.