store arraylist sharedpreferences android

Question

Is it a good idea to store a list of String with too many items in Sharedpreferences? Does it hurt app performance?

I'm doing this to store:

public boolean saveArray(List<String> contacts) {
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(_context);
    SharedPreferences.Editor editor = sp.edit();
    editor.putInt("Status_size", contacts.size());
    for (int i = 0; i < contacts.size(); i++) {
        editor.remove("Status_" + i);
        editor.putString("Status_" + i, contacts.get(i));
    }
    return editor.commit();
}

And to read:

public void loadArray(Context context) {
    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
    _validContactsPhones.clear();
    int size = sharedPreferences.getInt("Status_size", 0);
    for (int i = 0; i < size; i++) {
        _validContactsPhones.add(sharedPreferences.getString("Status_" + i, null));
    }
}

the only performance hit could come from `editor.commit();`. Call `editor.apply()` instead. — Peter Chaula, Nov 06 '16 at 11:10

score 1 · Accepted Answer · edited May 23 '17 at 12:13

No, its not a good idea to store a huge list of String like contacts in SharedPreference.

There's no specific limit of size for the stored SharedPreference in your application as its stored in the /data/data/[package name]/shared_prefs/[app name].xml. Since SharedPreferences are stored in an XML file it lacks the strong transaction support of SQLite. Hence I would recommend to store this kind of data in a SQLite database.

Another thing which needs to keep in mind that, the lowest size limit that I am aware of will be your amount of free heap space, as SharedPreferences reads that entire XML file's contents into memory.

The answer is mostly copied from here.

store arraylist sharedpreferences android

1 Answers1