how to restart downloading existing logs post an app crash / restart?

gnanda

Currently when I configure meta detector trackers for logging I save the route ids of each sensor configured and use them to set up the route handler on next connect just like below. 

 RouteManager route = mwBoard.getRouteManager(sharedPreferences.getInt(mwBoard.getMacAddress() + "_log_id", 0));

 route.setLogMessageHandler("log_stream", loggingMessageHandler);

I am able to reconnect and download logs at regular intervals as long as my app does not crash. If I restart downloading logs post an application crash and try to use the saved id it leads to a null pointer exception. Whats the right way to recover and start downloading existing logs at regular intervals post an app crash?

gnanda

Just to clarify post an app restart or crash  mwBoard.getRouteManager(saved_id) returns null. Hence I will get a null pointer exception if I try to set the log message handler. 

This wont happen if the app stays running and is periodically downloading logs from multiple trackers at regular intervals.

I just need to know how to handle the occasionally case where my app gets restarted. We plan to keep the app running for weeks at a time hence being able to recover from an app crash and continuing to download logs is important. 

Eric

You can serialize the MetaWearBoard object and restore it in the even of an app crash.  See:

https://mbientlab.com/androiddocs/2.8.6/metawearboard.html#serialization

http://www.polyglotprogramminginc.com/logging-thermistor-data-with-the-metawear/

gnanda

Thanks thats exactly what I was looking for.