Research And Development Distributed Multi-tier Application System For The Water Conservancy Fields Based On J2EE Technology

In the field of water resources, several problems need to be solved.1. flood disaster prevention;2. solving the drought and water shortage;3. water environment protection. The fact that the construction of water resources informatization system is not perfect suggests that the development degree of water resources is not high enough. So water resources informatization does not provide a full range of services for governments and people.These problems can be solved by using the advanced information technology. Water resources informatization system can be used to be taken advantage of water resources well, managed them effectively and analyzed and made decision by Water staffs.The distributed multi-tier framework should be used in water resources informatization system. The nation water resources information are concentrated in the Internet by computers. In the process of implementation of this technology, integrated software platform of the middleware system will be crucial to the Web system of distributed multi-tier framework.This paper studied that distributed multi-tier framework for the water resources informatization system based on J2EE technology.The specific contents are as follows:1. Using J2EE and EJB Technology in water resources informatization system.2. Implementing water resources informatization system of distributed multi-tier framework based on J2EE technology. The application framework is divided into five layers:data layer, data integration layer, service control layer, interface control layer and user interface layer.3. realizing Bean component reuse and obtaining heterogeneous database.4. Implementing distributed multi-tier system...