信息提供类Web服务基于查询重写的自动组合方法

Automatic composition of information-providing web services based on query rewriting

现有对Web服务自动组合的研究很少考虑信息提供类服务不同于一般服务的特点.文中提出一个简单,但具有明确语义的信息提供类服务功能模型,表达了该类服务不改变世界状态,有些输入输出参数不具有语义类型的特点;然后提出并实现了一个相应的自动组合方法.该方法以数据集成领域中一种查询重写算法MiniCon为基础,充分利用了前述特点,支持最基本的语义推理,能自动生成可直接运行的BPEL脚本.其性能特点与传统的基于搜索过程的方法具有互补性.在一类典型问题上进行的性能测试表明该方法具有相当强的实用价值.

Compared with normal web services,information-providing services have unique features that have seldom been considered in existing research on the automatic composition of web services.In this paper,we present a simple,yet well-formed,semantic-based capability model for information-providing web services,which can express such features as not modifying the world state and not requiring all input/output parameters to be supplemented with class information as semantics.We then present a corresponding automatic composition method derived from a query rewriting algorithm,MiniCon,used in the data integration field.This method adequately utilizes previous features,enables primitive semantic reasoning,and can generate executable BPEL scripts automatically.Performance of the method is complementary to traditional search-based ones.Experiments on a typical type of problem show that the method is usable in practice.