The Design And Implementation Of Mobile Police Based On J2ME/J2EE

With the development of economics, social progress and oncoming information age, police are constantly encountering many new problems, and challenging increasingly social demands. Police are burdened with many important tasks, such as the management of population, social security and traffic etc, which mean they need to query and deal with information outdoors. But the current system of police cannot meet active, mobile and timely needs. At present, police go through asking or taking notes because of no wireless communication which fit in with sophisticated operational environment, so that those who have escaped and cars' information cannot be checked on the spot. So police urgently need a portable and efficient system.The thesis compares and analyzes current technology of wireless platform's building, and presents a mobile police based on J2ME/J2EE and GPRS, which may gather, transmit and process information efficiently and timely outdoors. This thesis focus mainly on how to design and implement the system of mobile police, and concentrates on analyzing and discussing three of the system: wireless application architecture, the design of wireless client and the implementation of mobile police. Aiming at the problem of wireless application architecture, the thesis uses N-Tier architecture, that is, wireless client - WEB server - application server - database server. Aiming at the problem of wireless client's design, the thesis deeply parses current existing problems in the design of wireless client, then expands on the client architecture, the design for supporting online/offline operation, data models, data persistence, data refresh and synchronization, messaging and presentation. The thesis uses MVC, Adapter, proxy and chain of responsibility for client architecture, and analyzes their performance. Moreover, according to the characteristic of mobile police, the paper puts forward the solutions for data model, data persistence, messaging, and efficient strategies of data refresh and synchronization. The implementation of mobile police is demonstrated through the system's functions and the design of system's classes. Moreover, the implementations of several main classes are listed and the system is showed.