4.5 Application interface
An application was developed using Java applet technology. A Java applet is an application that can run on a web browser whilst the applet itself resides on a server. A number of Java classes were developed to support a customisation of the application system. Several tools of basic GIS rendering functions (e.g. zoom/pan) were developed.
5. The case study of London train network
The application of London train network was developed to find the shortest path for a journey between two stations. In this case, the weight for the shortest path is the distance of the geometry which is derived from the geometry of network features. An additional linear network feature calLED "alink" was set for a connection line between network features that can be interchanged at interchange stations. The rules of feature connectivity for London train network are defined as follows.
The semantics of network features are coded in the semantic schema as follows.
When the application starts up, it sends the request of the project of London train network to the integration engine servlet. This engine will read the project document. It then opens connections to data servers and retrieves all data defined in the project. It also creates a network family object which contains the rules of feature connectivity. Finally, all feature objects with the networ
