simpA-WS: a Simple Agent-Oriented Programming Model and Technology for Developing SOA and Web Services

Service-Oriented Architecture (SOA) is more and more recognised by the industry as the reference blueprint for building inter-operable, distributed enterprise applications based on open standards such as Web Services (WS). In the current state-of-the-art, the programming models for engineering SOA systems proposed by the leading industries are essentially component-based – typically, rooted in object-oriented abstractions and technologies. On the side, such a choice benefits from the well-know advantages of component-based software engineering and from the maturity of the available technologies; on the other, however, the abstraction level provided is inadequate to model some fundamental SOA aspects – such as autonomy, control-uncoupling, data-driven interaction, activities – as firstclass concepts. Such features can be modelled quite naturally by adopting an agent-oriented perspective. In this paper we describe simpA-WS, a Java-based framework for developing SOA/WS applications which adopts an agentoriented programming model based on the general-purpose Agents and Artifacts meta-model (A&A). simpA-WS makes it possible to conceive, design and program services (and applications using services) as workspaces where ensemble of pro-active, activity-oriented entities (agents) work together by exploiting different kinds of passive function-oriented entities (artifacts) used as resources, along with tools to support their business activities. Accordingly, we first present the simpA-WS framework and the related simpA language – an extension of Java aimed at capturing the A&A metaphors as first-class entities; we then show how agents and artifacts can be programmed in simpA and how SOA/WS applications can be programmed in simpA-WS; a simple running example is discussed for concreteness.