Contract design techniques for enterprise web services

The paper presents a collection of design techniques for building enterprise web services. By applying the techniques to web services development but not only the development increases reusability and productivity, but also the web services improve ability and compatibility. Enterprise web services require high grade of competency in designing web service contracts and A contract of web service formalizes an agreement between web service provider and consumer, in the forms of WSDLs, service schemas and policies. Contract - first method provides great potential of directly dealing with the contracts, a number of articles have been published regarding designing WS and XML schemas, however it is still risk for developers to find cookbooks or guidelines concentrated on designing web service contracts with contract-first method. To fill the gap, a set of web service techniques are introduced and deployed in practice, incorporating some best practices scattered in the web services community. These techniques cover to the most of the key aspects of web service, including consolidating service schemas in line with business entities, constructing coarse-grained namespaces, applying versioning over WSDLs and service schemas, and writing fine-grained filters with contracts.