Android - Using Shared Preferences in separate class?

Question

I want to save data using Shared Preferences in android. But I am looking to use separate class to do this task. I have implemented that class like below,

import android.content.Context;
import android.content.SharedPreferences;

public class SavePref {

    private Context context;

    public SavePref(Context context){
        this.context = context;
    }

    public void saveInt(String key, int value) {

        SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPref.edit();
        editor.putInt(key, value);
        editor.commit();

    }

}

But there is an error on getActivity(),

The method getActivity() is undefined for the type SavePref

How to solve this?
Thanks

Answer 1

getActivity() is a method of Fragment not of your SavePref. In your case the simple fix is to use the Context you are keeping as member variable to retrieve the SharedPreferences. An alternative to your approach is to avoid keeping the context as member variable, linking somehow the shared preferences to an instance of of your SavePref class, and have a static method

  public static void saveInt(Context context, String key, int value) {
        SharedPreferences sharedPref = context.getDefaultSharedPreferences(Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPref.edit();
        editor.putInt(key, value);
        editor.commit();
    }

and address the method like:

SavePref.saveInt(getActivity(), key, value);

from a Fragment or

SavePref.saveInt(this, key, value);

from an Activity. This way you don't need to instantiate SavePref every time you need to call saveInt, and you can avoid to store a reference to the Context.