Professional Visual Basic® 2008

Chapter 28. XML Web Services

This chapter begins with a short history of multi-tier architecture and network operating systems, a discussion of the early days of the "network as the computer," and a discussion of where system architecture is heading today. The reason for this diversion is to understand the rationale behind Web services.

The chapter next looks at a sample Web service and walks through the process of making it accessible to the Internet as well as accessing it from a client application — both with the Visual Studio IDE and using command-line tools. From there, the chapter moves on to a key feature of Web services: the Service Repository, Discovery, and Universal Description, Discovery, and Integration (UDDI) features that enable remote programmers to correctly access Web services.

Finally, the chapter delves into more in-depth topics during discussion of the four namespaces found in the .NET Framework class library that deal with Web services and how to utilize them with Visual Basic 2008. Moving on, the chapter covers topics such as security, transactions, and the downsides of any distributed architecture (including any downsides associated with the Web services model), followed by a short discussion of where you go from here and how to get there.

Introduction to Web Services

A Web service is a means of exposing application logic or data via standard protocols such as XML, or, more specifically, SOAP (Simple Object Access Protocol). A Web service comprises one or more ...