A portal component that contains a system resolving service is composed of two parts:
A java class that implements the following interfaces:
IService: The standard interface for all services
IDynamicSystemService: The interface for a system resolving service. This interface exposes one method, getAlternateSystem(), which returns a string that represents the PCD path to a system defined in the PCD.
A portalapp.xml file that defines the following:
The entries in the portal registry to create in order to indicate to the system landscape service for which aliases to invoke this service
The application properties that allow the service to function as a resolving service
The name of the resolving service and the class within the PAR that implements the service
A portal component can contain more than one system resolving service, if the component PAR file contains several java classes that implement the IDynamicSystemService interface.
A system resolving service can resolve more than one alias, if the portalapp.xml file creates several registry entries for the service.