Abstract: A framework of semantic Web service composition based on abstract template was proposed, and analysis of the template retrieval, data pre-processing and template adaptation modules of this framework were introduced in detail. In order to improve the accuracy of the template retrieval, the framework adopted the feature matching and graph matching methods in the similarity computation between the abstract template and the user’s request. Besides, it constructed the service dependency graph through the data pre-processing, deleted the useless services and verified the satisfiability of the user’s request. According to the service dependency graph, it implemented the automatic template adaptation, by using the Heuristic Plan Adaptation Algorithm (HPAA), and improved the adaptability and scalability of HPAA by providing the function of the flexible configuration of the heuristic strategies. Finally, the experiments on the different heuristic strategies show the effectiveness and reliability of HPAA when dealing with the large-scale problems.

Key words: semantic Web service, Web service composition, abstract template, heuristic plan adaptation

摘要： 提出一个基于抽象模板的语义Web服务组合框架，并详细分析了基于该框架的抽象模板检索、数据预处理以及模板修正的实现方法。为了提高模板检索的精确度，框架采用特征匹配和图匹配相结合的方法，实现了抽象模板和用户请求之间的相似度计算。同时利用数据预处理过程构建服务之间的依赖关系图，除去了冗余的服务，并事先验证了用户请求的可满足性。根据服务依赖关系图，框架使用启发式规划修改算法(HPAA)实现了模板的自动修正，并提供了对启发式策略的灵活配置，提高了服务组合的适应性和扩展性。最后对HPAA算法中所使用的启发式策略进行了实验，验证了算法在解决大规模问题上的适应性和可靠性。

关键词: 语义Web服务, Web服务组合, 抽象模板, 启发式规划修改