Web服务组合上下文模型

Context model for Web service composition

基于上下文感知计算,提出一种新颖的Web服务组合上下文模型。一方面,服务组合中的信息被定义为服务和用户上下文,前者又被区分为概要、会话和填充上下文;另一方面,采用多策略机制管理上下文。为此,定义了一种基于ECA规则的语言—服务扩展策略描述语言(PDL-S)。采用以上语言描述上下文管理策略和组合服务。该模型不但充分利用了上下文感知计算,而且具有良好的协作性、扩展性和灵活性。

Based on the context-aware computing, this paper proposed a novel context model for Web service composition. In this model, the information involved in the service composition was classified as service and user contexts, and the former was too distinguished as profile, conversation and grounding contexts; On the other hand, this paper adopted multi-policies to manage the contexts. Therefore, the policy description language extended by service was defined, and the language was based on （Event Condition Action） ECA rule. Not only the service policies were described by the above language, but also the description for composite service was realized by the language. The model not only sufiqcienfly utilizes the context-aware computing, but also has good cooperation, expansibility and flexibility.