服务web与云计算.pdf

Advanced web technology Web高级开发与应用技术 服务web与云计算 deeper Web Technology 服务概念的提出 SaaS Fudan MSE course, by Dai kaiyu Web Technology 将软件与服务分离 Fudan MSE course, by Dai kaiyu Web Technology SOA是什么? W3C : A set of components which can be invoked, and whose interface descriptions can be published and discovered. Fudan MSE course, by Dai kaiyu Web Technology 什么是服务?  A well-defined, invokable unit of business function  Accesses business data or facilitates a change of business data - from one valid and consistent state to another.  Defined using explicit interfaces - Independent of service implementations - Provides contract between service requestors and service providers  Invokable through common communication protocols - Provides interoperability and location transparency. 5 Fudan MSE course, by Dai kaiyu Web Technology 什么是面向服务的体系架构?  一个组件模型 将应用程序的不同功能单元（服务）通过 这些服务之间定义良好的接口和契约联系 起来。  接口是采用中立的方式进行定义的，它应 该独立于实现服务的硬件平台、操作系统 和编程语言。  构建在各种这样的系统中的服务可以以一 种统一和通用的方式进行交互。 6 Fudan MSE course, by Dai kaiyu Web Technology 为什么采用面向服务的体系架构?  A Service Oriented Architecture enables flexible connectivity of applications or resources by - Representing every application or resource as a service with a standardized interface - Enabling them to exchange structured information (messages, documents, ‘business objects’) - Mediating the message exchange through an Enterprise Service Bus  This flexibility enables new and exi