JGISFrame - a software framework for building GIS applications

The JGISFrame software framework enables efficient development of GIS-applications that use dynamic (time dependent) data. The framework conforms to a client/server model where the GIS-data is provided by the server and presented by the client. While a thin-client architecture is suited for a large number of users connected via high capacity communication channels, the thick-client approach used in JGISFrame is especially suitable in applications for mobile clients, where narrow bandwidth is the limiting factor and the communications load has to be minimised. The scalability of services, such as customised views for each user, is also easier to address when the user dependent computation is done on the client side. The JGISFrame is programmed in Java. Its design is based on experience gathered in a number of earlier maritime and logistics GIS projects performed at the VTT Information Technology. Generally accepted design patterns are applied in the architecture of the framework. The JGISFrame provides an abstraction of a GIS product, which consist of GIS objects encapsulating the actual GIS data, and user interface objects implementing the means of presenting that data to the user. A local storage for the GIS objects facilitates efficient retrieval within the framework. Queries to the local storage can be based on time, spatial location, or their combination. The framework approach for building GIS applications has proved to be very efficient in VTT Information Technologys projects. The iterative and parallel development process of the JGISFrame was also found very promising in developing reusable software. In our paper we locate the JGISFrame in the GIS domain, describe its architecture, its main functions, and the experience of applying it in applications that handle dynamic GIS-data.