P2P环境中基于语义的Web服务组合研究-智能与分布计算实验室

P2P环境中基于语义的Web服务组合研究

姓名	柯锋
论文答辩日期	2006.05.08
论文提交日期	2006.05.17
论文级别	硕士
中文题名	P2P环境中基于语义的Web服务组合研究
英文题名	Semantic-based Web Services Composition in P2P Environment
导师1	李瑞轩
导师2
中文关键词	Web服务组合;语义Web服务;Web服务本体语言;对等网;服务发布;服务调用
英文关键词	Web Services Composition;Semantic Web Services;Web Ontology Language for Services (OWL-S);Peer-to-Peer (P2P) Network;Service Publication;Service Invocation
中文文摘	Web服务和对等（Peer-to-Peer, P2P）计算都是近几年国内外非常热门的研究领域。研究人员尝试把这两种技术相融合，试图解决传统Web服务机制中存在的可靠性、扩展性等方面的不足。另外，Web服务的特性使得它非常适合于当今的商务应用集成，然而一个单独的Web服务很可能受限于其所拥有的服务能力，所以工业界和学术界都希望能够通过组合现有的Web服务来创造出新的服务功能，以满足更高要求的服务需求。这使得Web服务组合成为Web服务领域的一个重要研究方向，也使得研究P2P环境中的Web服务组合问题成为Web服务和P2P计算相结合领域研究的必然趋势。所谓Web服务组合，指的是从互联网中选取相对简单可用的Web服务并将它们组合成新服务的技术。研究表明，Web服务组合过程中存在许多关键性问题，诸如动态服务发现技术、复合服务执行技术和复合服务事务处理技术，而采用具有丰富语义信息的服务描述语言是解决这些Web服务组合关键问题的重要环节。利用基于语义的Web服务本体语言（Web Ontology Language for Service, OWL-S）描述Web服务，使Web服务成为机器可理解的。采用映射不同Web服务的OWL-S文档之间的关系的方法来完成Web服务组合，解决Web服务组合过程中产生的问题，如输入输出参数之间的异构问题。针对服务组合中的时间限制冲突问题可以通过扩展描述Web服务的OWL-S本体来解决。为了有效利用P2P网络的分布式特性，提出了P2P环境中基于语义的Web服务组合模型，在该模型中可以实现具有语义信息的Web服务的发布、组合和调用。实现了基于JXTA的Web服务组合原型系统WebPeer系统，加入了OWL-S文档的生成和发布功能，利用第三方软件Protégé和OWL-S Editor插件实现基于语义的Web服务组合操作以及组合完成后的调用工作。
英文文摘	Web Services (WS) and Peer-to-Peer (P2P) Computation are both hotspots in Computer Science all over the world. Some researchers have successfully leveraged WS and P2P to solve the problems such as the reliablity and scalability of the traditional WS mechanism. In addition, the characteristics of WS make itself very suitable for the integration of busyness application, but one alone WS is very easily restricted to its capability, so both the industry and academe hope to realize some new services for the complex requirements by composing the existing WSs. This makes Web Services Composition (WSC) becomes the hotspot in WS, and the trend of WSC within P2P environment is inescapable in the research area combining WSC and P2P. WSC means that selecting some simple and usable WSs in the Internet and composing them in order to generate some new WSs. Research work indicates that there are many key issues in the process of WSC, such as dynamic service discovering, composed service execution and composed service transaction processing, all of which are based on service description language. Using Web Ontology Language for Services (OWL-S) to describe Web Services improves the machine-understandability of WS. In order to complete WSC, the method of creating maps between OWL-S documents of different WSs is adopted, solving the problems in the process of WSC. And besides, expanding the ontology of OWL-S could solve the available time conflict problem in WSC. In order to benefit from the P2P Network, a semantic-based WSC model in P2P environment is presented, in which the Web Services publication, compostion and invocation could be realized. A prototype named WebPeer based on this model is implemented in JXTA platform, realizing the service publication by publishing OWL-S document and implementing the service composition and invocation by using some third-party softwares, such as Protégé and OWL-S Editor Plugin.