The Bidding System Based On J2ee Design And Realization

The main content of this thesis is based on the construction of bidding system in water conservancy engineering to explore the J2EE platform, in order to empolder the design pattern of highly efficient and stable, safe and reliable, favorable heritable and cross-platform-ability of the application systems software. Taking the J2EE technology as the guidance, it designs and implements a B / S structure of the 3-layer application framework system. This system through the Portal User Management, Web layer and layer combination of EJB security framework ensures the operational safety and achieves the data access interface of easily expansionary and uniform. By using the modular designing concept, it is able to circulate in different operation system and the situation of not revising a source program. Using the browser + middleware + application server + database server multi-tier architecture, demonstrates that logical, handling of traffic logic and data accessing logic separation. It possesses of complete security controlling structure. Universal data access structure shields the complexity of data access. It is easy to maintain and expand and Supporting a large number of users to access and a large amount of data storage, retrieval and management.The thesis firstly commences from the service model of the bidding. It states the demand of the bidding system and uses UML the UseCase diagram to describe. Through the need of the use-case analysis finds a permanence entity and the inter-relationship between them. Then it designs the date-base of the bidding system using entity-contact model and the third paradigm. Based on this, it analyses and designs the architecture of the bidding system. In the design it uses the J2EE application procedure architecture which is based on the MVC design pattern. In the module realization process, it uses multi-kinds of the pivotal technology of J2EE and the classical Java design pattern to realize the module coupling. In the design and implementation of the entire project process, uses the UML chart and so on as the description documents all the time, and unions the unified process to realize the project iteration and the increasing development.