How to save an instance of a custom class in onSaveInstanceState?

Question

I created an instance of a custom class RestaurantList to hold my data (a list of restaurant data received from a web service as json data).

How can I save it in

Answer 1

Custom class objects can be converted to JSON and stored in the bundle as a string. The following example is for Fragments.

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    Gson gson = new Gson();
    String json= gson.toJson(customClass);
    outState.putString("CUSTOM_CLASS", json);
}

public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    if(savedInstanceState != null) {
        String json= savedInstanceState.getString("CUSTOM_CLASS");
        if(!json.isEmpty()) {
        Gson gson = new Gson();
            CustomClass customClass = gson.fromJson(json, CustomClass.class);
        }
    }
}

For Activities, override onRestoreInstanceState method instead.