android use local service to refresh map UI

I don't need a strict code related answer I just need somebody to tell me what I am missing. My application has to retrieve from a web service (xmlrpc) the positions of some users I know and update their position on a MapView. So I decided to use a Service and an Activity extending MapActivity to show results. I thought about two solutions:

I ) start the service and make it ask every minute for these positions and send them to the activity as a bundle via intent. (This didn't work out well, since once shown I couldn't find a method to let the activity continue refresh itself until she stop receiving intents+data from the service)

II ) Incorporate a thread within the activity which starts the service via context.startService(...) every minute. And the MapUI refresh itself once the service send back an intent and stop itself. (Maybe I will fall in the same problem category as before I haven't tryied yet).

I am also giving directions (via maps.google ws) in this way I'd like to refresh only users positions on the map and save the route. What Am I missing do you have any suggestions? related to activities/services internal mechanics, don't know launch modes, use broadcast receivers or intent filters?开发者_运维问答 Thanks in advance

you may use AlarmManager with setRepeating(), that way you can send an Intent periodically to start/update your service. You should really separate fetching data (service) and updating the Activiy UI (from a DB?).

Otherwise you may have to bind your activity to the service, and communicate via an interface.

My 2 cents