Combining Web Services Research Articles

Service Component: A Mechanism For Web Service Composition Reuse And Specialization

Web services are becoming the dominant paradigm for distributed computing and electronic business. This has raised the opportunity for service providers and application developers to create value added services by combining web services. Several web service composition solutions have been proposed, e.g. WSFL and BPEL4WS. However, none of the existing solutions addresses the issue of service composition reuse and specialization, i.e. how applications can be built upon existing simple or composite services by reuse, restriction or extension. In this article we propose the concept of Service Component that packages together elementary or complex services and provides composition logic and semantics. Within the framework of Service Components we examine different aspects of composition reuse and specialization. A specification for web component reuse and specialization is provided, and possible solutions to support this specification are presented. To demonstrate our framework we provide an overview of ServiceCom, the tool that implements the Service Component concept, supporting reusable web service composition specification, combination, and execution.

Powerful combination: HIS and web services

Combining Web services with geographic information systems could help update and enhance the formerly static GIS technology in real time.

The Future of Web Services

Much of the Web's success can be attributed to its simplicity. It offers a straightforward means by which static information could be published and interconnected on a global basis. The Web Services initiative effectively adds computational objects to the static information of yesterday's Web and as such offers a distributed services capability over a network. Web Services have the potential to create new paradigms for both the delivery of software capabilities and the models by which networked enterprises will trade. Today's Web Services technology, useful though it is, will be enhanced over the next 2f years by the harnessing of Semantic Web technology to deliver a step change in capability. Web Services provide an easy way to make existing (or indeed new) components available to applications via the Internet. However, currently, Web Services are essentially described using semi-structured natural language mechanisms, which means that considerable human intervention is needed to find and combine Web Services into an end application. The Semantic Web will enable the accessing of Web resources by semantic content rather than just by keywords. Resources (in this case Web Services) are defined in such a way that they can be automatically ‘understood’ and processed by machine. This will enable the realisation of Semantic Web Services, involving the automation of service discovery, acquisition, composition and monitoring. Software agents will be able automatically to create new services from already published services, with potentially huge implications for models of eBusiness. Having identified limitations in current Web Services technology, this paper will survey existing research in Semantic Web Services, most notably USA's DAML-S initiative and the European WSMF work, and describe BT's research into creating a set of tools to support next-generation Semantic Web Services.

Building GIS web services on JXTA network

In recent years, Web services and Peer-to-Peer (or simply P2P) appear as two of the hottest research topics in network computing. On the one hand, by adopting a decentralized, network-based style, P2P technologies can make P2P systems enhance overall reliability and fault-tolerance, increase autonomy, and enable ad-hoc communication and collaboration. On the other hand, Web services provides a good approach to integrate various heterogeneous systems and applications into a cooperative environment. This paper presents the techniques of combining Web services and P2P technologies into GIS to construct a new generation of GIS, which is more flexible and cooperative. As a case study, an ongoing project JGWS is introduced which is an experimental GIS Web services platform built on JXTA. This paper also explores the schemes of building GIS Web services in a P2P environment.

Web services orchestration and choreography

Combining Web services to create higher level, cross-organizational business processes requires standards to model the interactions. Several standards are working their way through industry channels and into vendor products.