An efficacious software design method based on pattern and its application

In order to meet the requirement of the real-time data surveying of land utilization, an efficacious land survey GPS handset system was presented in this paper. In the system, a design pattern based framework was given out to increase its reusability, flexility and maintainability of Embedding GIS. Encapsulation for command like actions by applying COMMAND pattern was proposed for the problem of complex UI interactions. Integrating several GPS-log parsing engines into a general parsing framework was archived by introducing STRATEGY pattern. A network transmission module based network middleware was constructed. For mitigating the high coupling of complex network communication programs, FACTORY pattern was applied to facilitate the decoupling. Moreover, in order to efficiently manipulate huge GIS datasets, a VISITOR pattern and Quad-tree based multi-scale representation method was presented. It had been proved practically that these design patterns reduced the coupling between the subsystems, and improved the expansibility, flexility and maintainability.