Implementation of Non-java Based Interfaces to Embed Existing Models in Spatial Decision Support Systems - Case Study: Integration of Ms Excel-models in Iwegs -

This paper shows the programming and usage of computer based interfaces to embed models in modern SDSSs. The special focus is on the development and implementation of non-Java based interfaces which couple already existing Microsoft (MS) Excel-based models to individual designed SDSSs. To access MS Excel files within these developed systems, Java API POI-HSSF (by Jakarta) is used. HSSF provides a way to create, modify, read and write *.xls-spreadsheets. Besides that, this library supports cell-functions and -formulas.Based on the state-of-the-art software development and design approach MVC (Model-View-Controller), the interfaces are developed as processors. To meet the given requirements of accessing MS Excel, three processors are programmed: (i) GetXLSValueProcessor, (ii) SetXLSValueProcessor and (iii) RecalcXLSProcessor. Each of these processors connects the SDSSs to the *.xls -file, accesses a specific spreadsheet and uses the defined cells within that sheet. With these processors, it is possible to access and run complex Excel-based models from a user-friendly SDSS-Graphical User Interfaces (GUIs) by (i) providing the given input parameters from the Excel cells, (ii) allowing to edit the parameters in the SDSS-GUI, (iii) permitting to recalculate and run the model irrespective of the SDSS, (iv) getting the processed outputs from the model and finally (v) visualize them.In addition to the description of the development, preliminary results based on the developed SDSS IWEGS are shown.