PrefUtils is a base class intended to simplify and clarify the code relative to dealing with SharedPreferences. It is very simple and it is meant to be.

PrefUtils.java

package X.Y.Z;

import android.content.SharedPreferences;

/**
 * Created by ylemin on 21/11/15.
 *
 * This class is a bunch of recurring methods used when dealing with SharedPreferences.
 * It is intended to be a base class which receives the SharedPreferences instance from the child class.
 * There should only be one instance of SharedPreferences per app.
 */

public abstract class PrefUtils {

    /**
     * Abstract Methods
     */

    public abstract SharedPreferences prefs();

    /**
     * Public Methods
     */

    public void clear() {
        prefs().edit().clear().apply();
    }

    public boolean has(String key) {
        return prefs().contains(key);
    }

    public void set(String key, String value) {
        SharedPreferences.Editor editor = prefs().edit();
        editor.putString(key, value);
        editor.apply();
    }

    public String getString(String key) {
        return prefs().getString(key, null);
    }

    public void set(String key, Boolean value) {
        SharedPreferences.Editor editor = prefs().edit();
        editor.putBoolean(key, value);
        editor.apply();
    }

    public Boolean getBoolean(String key) {
        return prefs().getBoolean(key, false);
    }

    public void reset(String key) {
        SharedPreferences.Editor editor = prefs().edit();
        editor.remove(key);
        editor.apply();
    }

}