Design and Implementation of One WebGIS System Based on Oracle and Ajax Schema

摘要

WebGIS is the technology which publishes the geographic information service through the internet; it is changing more perfect after years with rich information, perfect user experience, which offer convenient geographic information services to people. This paper analyzes the technology and the schema used in the WebGIS today, and puts forward a schema which is based on oracle spatial, Ajax, JavaScript and so on. First, it uses oracle I Og to store the spatial data in the service, which provide GEOLOC field to store the spatial information and some spatial query and analysis functions and operators which make it easy and fast to realize spatial computation. Second it uses Ajax schema which realize asynchronous operations between client and service, and let the user do not need to wait before the service return the result. Third it uses the tile method that the large map is sliced up into many tiles and stored in the server. When the user visits the site, it just needs to download the several small tiles to visualize. Last, in the client, many operations such as pan, zoom and so on are realized based on the pure JavaScript. This schema solves the big data transmission through the internet, which reduce the response time when people visit the site and improve the users' experience.