Chaining of web services and its application in geographic information integration and visualization

Abstract

The rapid development of web services technology ushers Geographical Information Systems (GISs) into the era of geographic information web services (GIWS), which requires a scalable and extensible GISs model to deliver distributed geographic information and GISs functions integrated as independently-provided, interoperable services in a distributed computing environment. Several distributed services can be dynamically chained as a new service to accomplish a specific task. Such a model of service chaining is one of the most important research topics of next generation GISs. The paper highlights the issues of service chaining, the process of combining several distributed, interoperable GIWS dynamically to construct customized applications, and analyses characters of each pattern. Then, based on pattern of client-coordinated chaining, we design a service chaining which is developed in a J2EE development environment using web services technology, and construct a web services-oriented Geo-spatial data integration and visualization platform in order to integrate multi-sources and heterogeneous Geo-spatial data using Geography Markup Language (GML) and Geo-spatial data integration technology, and to visualize geographic information using Scalable Vector Graphics (SVG) and JavaScript technology. During the process of design, several GIWS are defined, and functions, interfaces and related methods of these services are discussed in detail. The paper focuses on the method for chaining distributed GIWS, the mechanism for geographic information dissemination and error handling. Finally, forest Geo-spatial Data which have two typical types of data E00 and Shapefile (SHP) was used to test the platform. The result indicates that using service chaining for multi-sources and heterogeneous Geo-spatial data integration and visualization can efficiently meet customized needs, but further research is needed for better application.