Modeling behavioral RESTful web service interfaces in UML

Abstract

A web service interface contains information about the names of the operations that can be invoked on the service and the input and output parameters of these operations. The Web Application Description Language (WADL) is a language to describe the interface of a web service that follows the Representation State Transfer (REST) architectural style. Currently, WADL descriptions do not describe the behavioral semantics of the operations neither ensure that the published interfaces follow the REST style, that is they are RESTful. In this paper, we present an approach to model the structural and behavioral interface of a RESTful web service using UML class and UML protocol diagrams. These models lead to RESTful interfaces that describe the behavior of operations in terms of preconditions and postconditions. The contracts can then be published in an extended version of the WADL language and used for documentation, stub generation, testing and monitoring purposes.