Android SharedPreferences limitations?

Question

I developed a game on Android. I am currently saving most of the game stats in a Database. However the app does not utilize more than a single row in the DB. I am now interested in introducing some new stats but this will cause my DB to re-install and thus clear out everyone's progress. In order to avoid this in the future I am considering storing the game stats with SharedPreferences instead. My question is how many different things can be stored that way before it becomes a problem. In total I would be storing around 40 values, all integers.

Answer 1

SharedPreferences are written to xml files, so the maximum size of a file on Android is how large a SharedPreferences xml file can be. I can safely say that 40 integer values will not be a problem.

The maximum size of a value in a SharedPreferences file is limited to the maximum size of the value you are attempting to store. (Meaning you can't put a String value that is longer than Strings can be in Java.)

The only thing I would suggest is making sure to batch the edits as much as possible (meaning don't .commit() each change) and also don't create a new editor for each change. (These are just good practices.)

SharedPreferences settings = getSharedPreferences(PREFS_FILE_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putInt("firstValue", mFirst);
editor.putInt("secondValue", mSecond);
editor.putInt("thirdValue", mThird);

// Commit the edits! (As infrequently as possible)
editor.commit();