ComplexPreferences.java

import android.content.Context;
import android.content.SharedPreferences;
import com.google.gson.Gson;

public class ComplexPreferences {

    private static ComplexPreferences complexPreferences;
    private Context context;
    private SharedPreferences preferences;
    private SharedPreferences.Editor editor;
    private static Gson GSON = new Gson();

    private ComplexPreferences(Context context, String namePreferences, int mode) {
        this.context = context;
        if (namePreferences == null || namePreferences.equals("")) {
            namePreferences = "complex_preferences";
        }
        preferences = context.getSharedPreferences(namePreferences, mode);
        editor = preferences.edit();
    }

    public static ComplexPreferences getComplexPreferences(Context context, String namePreferences, int mode) {

        if (complexPreferences == null) {
            complexPreferences = new ComplexPreferences(context, namePreferences, mode);
        }

        return complexPreferences;
    }

    public void putObject(String key, Object object) {
        if (object == null) {
            throw new IllegalArgumentException("object is null");
        }

        if (key.equals("") || key == null) {
            throw new IllegalArgumentException("key is empty or null");
        }

        editor.putString(key, GSON.toJson(object));
    }

    public void commit() {
        editor.commit();
    }

    public <T> T getObject(String key, Class<T> a) {

        String gson = preferences.getString(key, null);
        if (gson == null) {
            return null;
        } else {
            try {
                return GSON.fromJson(gson, a);
            } catch (Exception e) {
                throw new IllegalArgumentException("Object storaged with key " + key + " is instanceof other class");
            }
        }
    }
}

PrefUtils.java

import android.content.Context;
import android.content.Intent;

public class PrefUtils {

    public static UserResponse getUser(Context ctx) {
        ComplexPreferences complexPreferences = ComplexPreferences.getComplexPreferences(ctx, "appUser", 0);
        UserResponse currentUser = complexPreferences.getObject("loggedinUser", UserResponse.class);
        return currentUser;
    }

    public static void setUser(UserResponse currentUser, Context ctx) {
        ComplexPreferences complexPreferences = ComplexPreferences.getComplexPreferences(ctx, "appUser", 0);
        complexPreferences.putObject("loggedinUser", currentUser);
        complexPreferences.commit();
    }

    public static void signOut(Context ctx) {
        setUser(new UserResponse(), ctx);
        Intent i = new Intent(ctx, LoginActivity.class);
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        ctx.startActivity(i);
    }
}