服务接口描述是面向服务软件体系结构描述的关键问题之一,形式化描述方法是保证服务接口描述准确性的重要手段.目前的接口模型并不支持事务信息的描述.通过对已有Web服务接口模型进行扩展,提出了通过错误处理和补偿支持事务信息描述的接口模型,能够分别在特征层、会话层和协议层3个层面对服务的接口进行描述,然后提出了服务接口在3个层面的相容性和可替换性条件,并针对会话接口和协议接口提出了接口规约及其验证方法.该接口模型不仅能够支持准确的事务信息描述,而且还支持灵活、有效的接口规约验证.
Service interface description is one of the most important problems in service-oriented software architecture, and formal description methods are considered to be a promising approach for service interfaces. However, the existing interface models do not support transaction information description. By extending the model of Web Service Interface, this paper presents an interface model that can capture transaction information by means of fault handling and compensation. In this model, service interfaces can be specified at the signature, conversation and protocol levels. At each level, the compatibility and substitutivity are described formally. Furthermore, the interface specifications and corresponding verification methods are also presented at the conversation and protocol levels. The model supports precise transaction information description as well as flexible and effective verification for interface specifications.