Save ArrayList to SharedPreferences

Question

I have an ArrayList with custom objects. Each custom object contains a variety of strings and numbers. I need the array to stick around even if the user leaves

Answer 1

For String, int, boolean, the best choice would be sharedPreferences.

If you want to store ArrayList or any complex data. The best choice would be Paper library.

Add dependency

implementation 'io.paperdb:paperdb:2.6'

Initialize Paper

Should be initialized once in Application.onCreate():

Paper.init(context);

Save

List contacts = ...
Paper.book().write("contacts", contacts);

Loading Data

Use default values if object doesn't exist in the storage.

List contacts = Paper.book().read("contacts", new ArrayList<>());

Here you go.

https://github.com/pilgr/Paper