How to save Array list with model class in shared preference?

Question

private ArrayList<PhotoInfo> imagelist;


imagelist = new ArrayList<>();

imagelist = response.body().getPhotos();

I have to save images in shared preference

and retrieve from as Arraylist

Answer 1

Hey I made this easy methods for Save & Get any custom model's ArrayList into SharedPreferences.

Gson dependency required for this:

implementation 'com.google.code.gson:gson:2.8.5'

Save any custom list into SharedPreferences:

public void saveMyPhotos(ArrayList<PhotoInfo> imagelist ) {
    SharedPreferences  prefs = PreferenceManager.getDefaultSharedPreferences(this);
    SharedPreferences.Editor editor = prefs.edit();
    try {
        Gson gson = new Gson();
        String json = gson.toJson(imagelist);
        editor.putString("MyPhotos", json);
        editor.commit();     // This line is IMPORTANT !!!
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Get all my saved photos from SharedPreferences:

private ArrayList<PhotoInfo> getAllSavedMyPhotos() {
    SharedPreferences  prefs = PreferenceManager.getDefaultSharedPreferences(this);    
    Gson gson = new Gson();
    String json = prefs.getString("MyPhotos", null);
    Type type = new TypeToken<ArrayList<PhotoInfo>>() {}.getType();
    return gson.fromJson(json, type);
}