Store a List or Set in SharedPreferences

Question

My app has a list of String values (of some 5-20 characters each), that I have to store persistently. The SharedPreferences seem to me the most appropriate, as it\'s a short

Answer 1

Using this object --> TinyDB--Android-Shared-Preferences-Turbo its very simple.

TinyDB tinydb = new TinyDB(context);

to put

tinydb.putList("MyUsers", mUsersArray);

to get

tinydb.getList("MyUsers");

Answer 2

If you know the order of the list entries and/or it doesn't matter you can "glue" them all into a single String with a separator of your choice and then store it with SharedPreferences. After loading it back you would split the String into the entries based on your separator. Something like String listEntries = "enty1;entry2;entry3" (semicolon as separator in this case). But no idea about performance issues.

Answer 3

I found the easiest solution to store and retrieve a list of items from SharedPreferences is to simply serialize / deserilaize the array into / from JSON and store it into a string setting.

Gson comes really handy doing it.

READ:

SharedPreferences prefs = context.getSharedPreferences("settings", Context.MODE_PRIVATE);
String value = prefs.getString("list", null);

GsonBuilder gsonb = new GsonBuilder();
Gson gson = gsonb.create();
MyObject[] list = gson.fromJson(value, MyObject[].class);

WRITE:

String value = gson.toJson(list);
SharedPreferences prefs = context.getSharedPreferences("settings", Context.MODE_PRIVATE);
Editor e = prefs.edit();
e.putString("list", value);
e.commit();