save arraylist in shared preference

Question

I am storing values in ArrayList and pass it to using bundle to next Fragment, and there I set values to my TextView, till here it wor

Answer 1

An alternative solution (just thought of it):

If you have an array called addtos and you want to add the array to shared preferences, since the variable is represented in the dictionary as a String, you could append the array index to the end of that string.

e.g -

Storing

for(int i = 0; i<addtos.size(); i++)
    prefsEditor.putString("addtos"+i, addtos.get(i));

Receiving

int i = 0;
while(true){
    if(prefs.getString("addtos"+i, "")!=""){  // or whatever the default dict value is
        // do something with it
        i++;
    }else{break;}
}

Seems ok to me, if anyone sees a problem with this, let me know.

Also, no need for ArrayLists

Answer 2

Use tinydb. check following link you might get some idea. https://github.com/kcochibili/TinyDB--Android-Shared-Preferences-Turbo

using tinydb you can store array in local db.

Answer 3

First download Gson.jar from below link and then add it to libs folder of your project

http://www.java2s.com/Code/Jar/g/Downloadgson17jar.htm

then put That ArrayList in the Class and make object of that class then you can save that object to SharedPreferences like below

public static void save_User_To_Shared_Prefs(Context context, User _USER) {
    SharedPreferences appSharedPrefs = PreferenceManager
            .getDefaultSharedPreferences(context.getApplicationContext());
    SharedPreferences.Editor prefsEditor = appSharedPrefs.edit();
    Gson gson = new Gson();
    String json = gson.toJson(_USER);
    prefsEditor.putString("user", json);
    prefsEditor.commit();

 }

above code is an example _USER objext contain ArrayList.

And to read the object have a look at below code

 public static User get_User_From_Shared_Prefs(Context context) {

    SharedPreferences appSharedPrefs = PreferenceManager
            .getDefaultSharedPreferences(context.getApplicationContext());
    Gson gson = new Gson();
    String json = appSharedPrefs.getString("user", "");


    User user = gson.fromJson(json, User.class);
    return user;
} 

now when you want to get the _USER object call the above function and in result you will have the object and in that you will have the ArrayList

Answer 4

Complete example of storing and retrieving arraylist in sharedpreference:http://blog.nkdroidsolutions.com/arraylist-in-sharedpreferences/

  public void storeFavorites(Context context, List favorites) {
    // used for store arrayList in json format
            SharedPreferences settings;
            Editor editor;
            settings = context.getSharedPreferences(PREFS_NAME,Context.MODE_PRIVATE);
            editor = settings.edit();
            Gson gson = new Gson();
            String jsonFavorites = gson.toJson(favorites);
            editor.putString(FAVORITES, jsonFavorites);
            editor.commit();
        }


        public ArrayList loadFavorites(Context context) {
    // used for retrieving arraylist from json formatted string
            SharedPreferences settings;
            List favorites;
            settings = context.getSharedPreferences(PREFS_NAME,Context.MODE_PRIVATE);
            if (settings.contains(FAVORITES)) {
                String jsonFavorites = settings.getString(FAVORITES, null);
                Gson gson = new Gson();
                BeanSampleList[] favoriteItems = gson.fromJson(jsonFavorites,BeanSampleList[].class);
                favorites = Arrays.asList(favoriteItems);
                favorites = new ArrayList(favorites);
            } else
                return null;
            return (ArrayList) favorites;
        }


        public void addFavorite(Context context, BeanSampleList beanSampleList) {
            List favorites = loadFavorites(context);
            if (favorites == null)
                favorites = new ArrayList();
            favorites.add(beanSampleList);
            storeFavorites(context, favorites);
        }


        public void removeFavorite(Context context, BeanSampleList beanSampleList) {
            ArrayList favorites = loadFavorites(context);
            if (favorites != null) {
                favorites.remove(beanSampleList);
                storeFavorites(context, favorites);
            }
        }

Answer 5

You can use gson:

To Save Preferences:

 public void save_User_To_Shared_Prefs(Context context, List<User> users) {
        SharedPreferences settings;
        Editor editor;

        settings = context.getSharedPreferences(PREFS_NAME,
                Context.MODE_PRIVATE);
        editor = settings.edit();

        Gson gson = new Gson();
        String jsonUsers = gson.toJson(users);

        editor.putString(USERS, jsonUsers);

        editor.commit();
    }

To get Preferences:

public ArrayList<User> getUsers(Context context) {
        SharedPreferences settings;
        List<User> users;

        settings = context.getSharedPreferences(PREFS_NAME,
                Context.MODE_PRIVATE);

        if (settings.contains(USERS)) {
            String jsonUsers = settings.getString(USERS, null);
            Gson gson = new Gson();
            User[] userItems = gson.fromJson(jsonUsers,
                    User[].class);

            users = Arrays.asList(userItems);
            users= new ArrayList<User>(users);
        } else
            return null;

        return (ArrayList<User>) users;
    }

To add user:

public void addUser(Context context, User user) {
        List<Product> favorites = getUsers(context);
        if (users == null)
            users = new ArrayList<User>();
        users.add(user);
        save_User_To_Shared_Prefs(context, users);
    }