The Research Of Module Of Vector Graphic Of ComGIS Based On ORDBMS

In order to finish the design of the module of vector graphic of ComGIS based on Oracle Spatial, design of components of the module of vector graphic and constuctures of components based on Design Patterns and Design by Contract are discussed especially. On the basis of analyzing key concepts of GIS, technologies of COM and Oracle Spatial, the system structure of ComGIS based on Oracle Spatial is designed. Utilizing the method of Object-Oriented Analysis, the classes of GIS based on Oracle Spatial and the interfaces of main components are designed. Based on the analyse of applying design pattern in ComGIS,a lots of pattens have been applied in practice .By this way,it improves the resusable internal and external of components.Finally,the technology of implement ComGIS based on Contract has been discussed ,it puts forward the solution project which instanced by data access part. .By this way,it improves the correctness of components and defines the functions and responsibility of components.