On onLocationChanged event I want to save my GPS route (Latitude , Longitude). Later I want to load this data and draw the route.
Who is the best way to do this, by
The best way of storing double values in SharedPreferences without losing precision is:
Transform to bit representation to store it as long:
prefsEditor.putLong("Latitude", Double.doubleToLongBits(location.getLatitude()));
To retrieve, transfrom from bit representation to double:
double latitude = Double.longBitsToDouble(prefs.getLong("Latitude", 0);
However, I think that if you want to store a big amount of points is better using a SQLite database than saving each coordinate in a Key-Value pair in SharedPreferences or serialize the array in XML and write it to a file or to SharedPreferences. The database offers you the advantage of loading in memory only the points within the area you are displaying in the map, so you can save memory.