Two-way Web service: from interface design to interface verification

In this paper, we introduce a theoretical framework for two-way Web service (WS) interaction and interface design based on the concepts of operation reversal and XML type generalization. Under this theoretical framework, two generic types of interface solutions in two-way WS interaction, i.e. tightly coupled (TC) interface and loosely coupled (LC) interface, are formally defined and studied. The proposed theoretical framework is used to design, derive and verify WS interface for full duplex two-way WS interaction. An algorithm of interface verification is described that allows effective WS interface design and verification to support asynchronous two-way WS operation and event notification. The interface verification algorithm in our approach utilizes verification by derivation and verification by content to validate the client interface in two-way WS interaction. Use case studies are performed for both TC and LC interface solutions. A generic infrastructure based on two-way Web service application proxy (2SAP) is described and implemented. The proposed approach is applied to applications of realizing ECMA-348 for WS enablement of telecommunication.