Research And Implementation Of GIS Web Services Based On Ajax/REST

Geographic Information System (GIS) is a computer system that can retrieve, store, query, process, analyze, and display geographic data and related information. Web is a platform on which people can share and exchange information. The combination of Web and GIS is always a hot issue to researchers in the GIS field. The era of Web2.0 brings some new application techniques and conceptions. How to use the new techniques to solve the old problems of GIS--such as, how to share heterogeneous spatial data? How to speed the display of spatial data on browser?--is the main content of this thesis.REST is a new style of Web Services. It took all information on server as Resources. Then give each resource a unified identifier. Client can use these identifiers to access resources and to get the Representation of the resources. Ajax is a new technique to develop Web Applications. It allows the information processed asynchronously between client and server. Users can do other things while waiting the data transported from servers.Based on these two techniques, the thesis put the focus on the designing an architecture of GIS Web Services. And put an instance to the architecture to verify the usability.First, the dissertation took a look back into the history of the combination of Web and GIS, and discovered the difference between Web GIS and GIS Web Services. Then analyzed the shortcoming of Web GIS and got a conclusion of the trend of Web GIS to GIS Web Services.Then, the dissertation studies the characteristics of the two new techniques and their impact to GIS. (1) Compare and contrast the two types of Web Services (WS): WS based on the SOAP protocol stack and RESTful WS. Draw a conclusion that the latter on is more close to basic Web protocol and is easier for GIS application to be put on Web. (2) Case study: we took a classic GIS Web Service—Google map—as an example of use of Ajax. We analyzed the advantage of Ajax of the use in the GIS Web Services.After that, the dissertation designs GIS Web Services architecture based on Ajax/REST. The server in the architecture is called"data center", and the client can use the data center's information to mashup their own new services.In the end, the dissertation put the architecture into use and the case is improved that the usability of the architecture.