Put and get String array from shared preferences

Question

I need to save on shared preferences some array of Strings and after that to get them. I tried this :

prefsEditor.putString(PLAYLISTS, playlists.toString()); where playlists is a String[]

and to get :

playlist= myPrefs.getString(PLAYLISTS, "playlists"); where playlist is a String but it is not working.

How can I do this?

score 105 · Accepted Answer · answered Nov 01 '11 at 10:49

105

You can create your own String representation of the array like this:

StringBuilder sb = new StringBuilder();
for (int i = 0; i < playlists.length; i++) {
    sb.append(playlists[i]).append(",");
}
prefsEditor.putString(PLAYLISTS, sb.toString());

Then when you get the String from SharedPreferences simply parse it like this:

String[] playlists = playlist.split(",");

This should do the job.

answered Nov 01 '11 at 10:49

Egor

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Then how do you do getString()? What do you use as the second parameter in that? – IgorGanapolsky Apr 11 '12 at 16:42
@IgorG., It's pretty much up to you, implement your own logic of checking the number of items in that string. – Egor Apr 11 '12 at 17:31
4

the problem of this is that strings can't contains the character used to separate them from each other. An encoding is required before using this method. – Mario Lenci Jan 02 '13 at 13:46
5

@Mario Lenci, I use ";;delimiter;;" as separate string – dimetil Sep 06 '13 at 18:51
@dimetil this looks ugly. And still if somebody type ";;delimiter;;" you have a problem. (not mentioning about the fact that you waste memory, and CPU to parse this thing) – Paweł Brewczynski Jan 05 '14 at 14:37
1

So what is your solution bluesm? – Greg Ennis Jan 20 '14 at 22:13
the saving part could be simplified to: prefsEditor.putString(PLAYLISTS, TextUtils.join(",", playlists)); – rbs Oct 01 '16 at 09:51

score 37 · Answer 2 · answered Mar 26 '15 at 14:51

37

From API level 11 you can use the putStringSet and getStringSet to store/retrieve string sets:

SharedPreferences pref = context.getSharedPreferences(TAG, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = pref.edit();
editor.putStringSet(SOME_KEY, someStringSet);
editor.commit();

SharedPreferences pref = context.getSharedPreferences(TAG, Context.MODE_PRIVATE);
Set<String> someStringSet = pref.getStringSet(SOME_KEY);

answered Mar 26 '15 at 14:51

MikeL

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i thinks it is easier than accepted answer if anyone building app from API level 11 or higher. – Sayem Jul 29 '15 at 08:57
16

The problem is that Set is not ordered. In contrast to String[] – Tomáš Hubálek Jul 30 '15 at 14:57
I have a string array with values as a,0 b,1 now on the click in settings, I want to changes these values. How to use putStringSet in this. – pa1pal Mar 30 '16 at 17:47
@pa1pal, you should probably create a new question and explain there exactly what you want to do and what you did up until now – MikeL Nov 27 '16 at 09:09

score 9 · Answer 3 · edited May 23 '17 at 12:18

9

You can use JSON to serialize your array as a string and store it in the preferences. See my answer and sample code for a similar question here:

How can write code to make sharedpreferences for array in android?

edited May 23 '17 at 12:18

Community

1
1

answered Nov 01 '11 at 10:50

Jeff Gilfelt

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score 4 · Answer 4 · answered Dec 23 '17 at 15:53

HashSet<String> mSet = new HashSet<>();
                mSet.add("data1");
                mSet.add("data2");
saveStringSet(context, mSet);

where

public static void saveStringSet(Context context, HashSet<String> mSet) {
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
    SharedPreferences.Editor editor = sp.edit();
    editor.putStringSet(PREF_STRING_SET_KEY, mSet);
    editor.apply();
}

and

public static Set<String> getSavedStringSets(Context context) {
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
    return sp.getStringSet(PREF_STRING_SET_KEY, null);
}

private static final String PREF_STRING_SET_KEY = "string_set_key";

As noted by @Tomáš Hubálek, `Set` is not ordered and so could change the behavior of your program. — Dale, Jun 19 '18 at 16:05

Hitesh Tarbundiya · Answer 5 · 2020-10-11T14:57:06.463

Store array list in prefrence using this easy function, if you want more info Click here

 public static void storeSerializeArraylist(SharedPreferences sharedPreferences, String key, ArrayList tempAppArraylist){
    SharedPreferences.Editor editor = sharedPreferences.edit();
    try {
        editor.putString(key, ObjectSerializer.serialize(tempAppArraylist));
        editor.apply();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

And how to get stored array list from prefrence

public static ArrayList getSerializeArraylist(SharedPreferences sharedPreferences, String key){
    ArrayList tempArrayList = new ArrayList();
    try {
        tempArrayList = (ArrayList) ObjectSerializer.deserialize(sharedPreferences.getString(key, ObjectSerializer.serialize(new ArrayList())));
    } catch (IOException e) {
        e.printStackTrace();
    }
    return tempArrayList;
}

This link is broken. ObjectSerializer is not a class in Android. — Eugene Kartoyev, Oct 09 '20 at 20:51

Put and get String array from shared preferences

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