In some occurrences the GSN the web service interface might be disabled by default. You can easily check this by

• installing and starting GSN by [wiki:install-gsn source] or [wiki:installer binary]
• visit http://localhost:22001 to check whether GSN is running (given that the GSN port was not changed)
• visit http://localhost:22001/services/GSNWebService?wsdl where the WSDL should be published
• if an XML (the web service definition) is displayed, all is fine and the web service is running
• if you get a 404 error instead, the web service needs to be enabled

in order to enable the web service interface you have to edit the config file for it

• if still running, stop gsn
• open the config file at webapp/WEB-INF/web.xml
• there are 2 areas to uncomment (you can uncomment by removing the comment tags which are <!-- and --> )
• one is almost at the beginning of the file, starting and ending with the tag <servlet>
• one is rather at the end of the file, starting and ending with the tag <servlet-mapping>
• after closing and saving the file try to start GSN again and visiting above mentioned

The web service interface uses SOAP 1.2 for invoking methods. You have to send a soap envelope with the parameters to the respective service address such as http://localhost:22001/services/listVirtualSensorNames. There are various existing libraries for easily creating your own web service clients.

For a detailed description of the possible web service calls use the standard GSN Web Service reference for the standard GSN Web Service]

This paragraph is a short developer documentation. Usual GSN users can safely ignore it.

In order to change the standard web service

• change the WSDL at webservices/standard/META-INF/GSNWebService.wsdl to your needs
• from the build.xml in the root directory run the ant task dev-ws-wsdl2java
• from the build.xml in the root directory run the ant task dev-ws-package
• the new ws package should have been generated at webservices/standard/GSNWebService.aar
• copy the file GSNWebService.aar to webapp/WEB-INF/services/GSNWebService.aar
• run GSN; the new WSDL should be published at http://localhost:22001/services/GSNWebService?wsdl
• optional: you may run the ant task "clean" from standard/build.xml to clean the source tree from non-necessary files