I've been looking through many questions about services, but I couldn't find one that suited me. I need a service that both starts on BOOT_COMPLETED (not bound to an Activity) and runs ALL the time (therefore I can't user AlarmReceiver). I know it might drain my battery but so far I don't care. It is just for research purposes.
I have a service that monitors sensor's data. What I managed to do so far was: either start the service as a regular Activity, but it runs only for +-20s and it is stopped (I think the SO cuts it down to release its memory); or start a service that runs in foreground. It worked to keep the process running, however the class that actually runs the service somehow was not started, besides an annoying notification which is required.
The code I refered as the one that runs the service in foreground was taken from here: Implement startForeground method in Android
I mean, how does an app like WhatsApp run constantly? Is it running in foreground? Because looking at Settings it seems the service is very stable, and it does not show any permanent notification, since it is not possible for a foreground service run without one. ( How to startForeground() without showing notification? )
Any advice?