Map-based Advertisement System in the World Wide Web

This paper describes the design and implementation of a World Wide Web (WWW) application that allows users to look for classified advertisements based on the locations of the advertised objects. The application lets users limit a search to a certain area by working directly on a map. The locations of the advertised objects are visualized on the map. New WWW browser programs allow interactive programs written in the Java language to be included in WWW services. More traditional CGI (Common Gateway Interface) scripts can also be used. Database systems can be called from other programs and can provide a basis for the advertisement service. Making use of geographic information systems in a similar way has not been as straightforward until lately. The advertisement visualiser application includes a client written in the Java language and a CGI program that looks for maps and advertisements stored in a server computer. The application also includes information that is necessary for showing any street addresses on the map. The system is already in routine use through a WWW service provided by Helsingin Sanomat, the largest newspaper in Finland. The database of the service consists of housing advertisements in the larger Helsinki area.