The Design And Realization Of Urban Traffic Information System Data Access Middleware

Transportation systems become complex entities through information construction, which integrate many technologies and systems. There are many kinds and large quantities data that come from multiple sources. Data management and using has characteristics, such as multi users, distributed and networked. And the data depends on spatial and time. So it has important realistic meaning to manage and utilize the data effectively. That can provide data services for traffic management, plan, forecast, control, analysis, etc.The design and implementation of data access middleware is based traffic practical application. Characteristics of the data resource are analysed. The strategy is presented how to organize and storage the data. Data access middleware based Middleware technology and user-defined communication protocol is mainly discussed in paper. System implemented communication, parallel access, data consistency, Database connection pool, map data access, real-time traffic information service, device control information service and direct command service. Data access middleware provides excellent data services for Urban Traffic Fast-Response System.Data access interface is redesigned based on J2EE platform in order to enhance system's current. A part of data access component are implemented on PKUAS which is an application server developed by Peking University.