Calling Adapter Service from Portlet

Hi Guys, Is it possible to call an adapter service in IS from a portlet or does it need to be wrapped with a flow service? Specifically I want to call a service(adaptor or flow) to fill a dropdown box. Thanks

Best practice would be to wrap the adapter service to perform error handling, retries logic, etc.

Are there any nice howto’s on this practice?

None that I know of.