Research On Component Assembly Technology Based On Workflows And Web Services

As the information technology develops, it is difficult for traditional software development technology to adapt to the increasing degree of the scale and complexity of software products. Based on such reality, software reuse technology came into being, among which, component technology is the most important one. Through the application of component assembly, component-based software development (CBSD) was born. A large number of components have been produced by various component production facilities. These components are quite different in the format, description, and structure as well as access method, thereby causing certain problem on the calling, sharing and interoperation of the system which is combined with components from multiple sources.The comprehensive assessment and choice based on QoS (quality of service) attribute of the service is the key of Web service assembly. There are many parameters affecting QoS attribute of the service. Through analysis, the general QoS attribute of Web service, including execution time, execution cost, credit as well as QoS attribute concerning domain, that is domain availability and domain suitability, all the above five attributes are chosen to form the minimum completeness attribute QoS set of Web service. Analytic hierarchy process is applied to conduct the comprehensive optimization and selection of Web service. In order to better conduct the comprehensive optimization of various parameters, the five parameters of different co-domain in the minimum attribute set should go through a process of "normalization", and then the judgment matrix of alternative layer should be constructed. The effect weight of the parameters is different, so according to the qualitative judgment of some experts,1-9scaling method is adopted to transform the qualitative judgment of the parameter effect to its quantitative analysis; then the judgment matrix of criterion layer should be constructed. So the calculating system of analytic hierarchy process is created. Through calculation, the optimization of Web service can be realized.The Web Service based on the workflow technology realizes the separation between the operation process logic and the operation activities, which flexibly support the construction and recombination of the operation system. In the construction of operation system, Web Service which realizes operation functions is defined as Functional Web Service (FWS); the one realizing transferring of operation process is defined as Controlled Web Service (CWS). The definition of workflow is based on workflow management system, which establishes and activates operation process by using the workflow engine, asks for Web Service request and selection in process nodes and makes the operation process instantiated and executed. When the operation process changes, operation process will be recreated, and the reconstruction in the operation process will be adapted flexibly.Finally, with tracking system of the meat quality as application background and based on the operation process of the meat quality traceability constructed by workflow technology, Functional Web Service and Controlled Web Service of tracking system of the meat quality will be evaluated and constructed by using AHP (Analytical Hierarchy Process) based on QoS, so as to verify the feasibility by realizing prototype system.