In the app I am working on, I have an AlarmManager that starts a Service at specified times and intervals. The Service uses some data I send in the Intent to read/write the SQLite database, make a Notification and send an SMS. I've had a problem that when the device goes into "deep sleep" and I use the device again, I get a force close with a NullPointerException on the Intent in the Service. As I've done some research, I've had several questions about how a Service works that I haven't been able to answer:
1) I realized that I was using the deprecated onStart method for a Service. I am going to switch to onStartCommand with START_REDELIVER_INTENT flag (think this was the null exception I was getting because the Service was trying to restart with the old onStart and not getting the original Intent). My question is this: Should I put the work the Service does in the onStartCommand or in onCreate? Is there any functional difference?
2) Considering what I am doing in my Service, is this enough work to put in its own Thread?
3) Do I need to specifically call stopSelf? If so, where is the best place to call it?
4) This one is more ambiguous: To my knowledge, I had canceled all of the alarms registered and after deep sleep, I still got the null exception for a Service. Is there any reason the Service would still get run even though I never triggered it with an alarm?
Please ask any clarifying question if necessary. I haven't posted code because most of it is generic for starting and consuming a Service, but if you want to have a peek, let me know. Thanks.
You should use IntentService instead of regular old Service. It does all its work in a background thread and stops itself automatically when it runs out of work.