Based On Qos In Web Services Dynamic Combination Of Technology And Tools

SOA (Service-Oriented Architecture) is a component model based on Web Service, it is becoming the predominate architecture for enterprise services'development and compliment. Web Service uses a loosely coupled integration model, it is the first choice of service software development because of its better scalability, and lower developing cost, and has broad practical value and business prospects. QoS is the indicator to describe the performance of Web Service. During the process of service selection, service consumers can choose the most suitable Web Service through the QoS technology to meet their demands.This paper researched on the Web Service composition modeling tool, which is the sub-topic of "863"national key project "process-management-oriented software production line" undertaken by our institute. The main work includes the following aspects:1. Firstly, this paper analyzed the relative technologies of Web Service composition as well as the shortcomings of existing tools, demonstrated the essentiality of QoS, and proposed an extended type of WSDL (Enhanced-WSDL).2. Secondly, the formal QoS description and two kinds of factors were proposed in this paper. Aslo, the QoS calculation method and calculation model based on service comsumers'expectations were raised. Besides, the service selection model and algorithm were put forward.3. Thirdly, QoS-based Web Service dynamic composition algorithm was proposed.4. Finally, Web Service composition tool based on C/S structure was designed and implemented. This tool could support service consumers to choose the most suitable service to complete Web Service composition.