This book presents a methodology to model and specify the data aspect of Web services, as it is overlooked by current standards for specifying Web services. The formal specification enables verification of service behavior, and the proposed methodology is based on formal methods and design-by-contract techniques.

The Web has evolved from an information sharing medium to a wide-scale environment for sharing capabilities or services. Currently, URLs not only point to documents and images, but are also used to invoke services that potentially change the state of the Web. Major online...