Android: String set preference is not persistent

Question

I have a problem with storing string set preference. I have these utility methods for storing:

public static void putStringSet(SharedPreferences pref, Editor         


        

Answer 1

This has a ridiculous amount of duplicates - I bet that you do :

set = prefs.getStringSet("X", new HashSet<String>());
set.add("yada yada");
prefs.putStringSet("X", set);

In short android sees that set and the one inside refer to the same set and does nothing. Correct ?

See: Misbehavior when trying to store a string set using SharedPreferences

Answer 2

My condition is very similar to yours, the only difference is when restart the app, preference contains A, B, C, but when reinstall it or reboot the phone, B&C are gone.

I also tried replace commit() with apply(), as this post adviced SharedPreferences not persistent , but still not to work.

I solved this problem by remove & commit the preference before replacing it:

editor.remove("StringSetKey");
editor.commit();

editor.putStringSet("StringSetKey", newSet);
editor.commit();

Ps: you can type adb pull /data/data/<packagename>/shared_prefs/xxxx.xml in cmd line to see if the commit() really works

Pps: I think this is a bug with putStringSet....

hope this will help you ;)