Preferences.java

package com.alexvasilkov.android.commons.prefs;

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

/**
 * Singleton object for simple {@link SharedPreferences} object creation.<br/>
 * Don't forget to initialize it by calling {@link #init(android.content.Context, String) init method} in your {@link android.app.Application} class.
 */
public class Preferences {

    private static Context sAppContext;
    private static String sDefaultPrefsName;

    /**
     * Stores application context for later use.
     */
    public static void init(Context context) {
        sAppContext = context.getApplicationContext();
    }

    /**
     * Stores application context and default prefs name for later use.
     */
    public static void init(Context context, String defaultPrefsName) {
        sAppContext = context.getApplicationContext();
        sDefaultPrefsName = defaultPrefsName;
    }

    /**
     * Returns {@link SharedPreferences} object with default prefs name provided in {@link #init(android.content.Context, String) init method}
     */
    public static SharedPreferences prefs() {
        return prefs(sDefaultPrefsName);
    }

    /**
     * Returns {@link SharedPreferences} object with provided name and mode = <code>Context.MODE_PRIVATE</code>.
     */
    public static SharedPreferences prefs(String name) {
        if (sAppContext == null)
            throw new RuntimeException("Preferences should be initialized by calling Preferences.init(...) method");
        if (name == null) name = "null"; // To be compatible with updated SharedPreferences logic
        return sAppContext.getSharedPreferences(name, Context.MODE_PRIVATE);
    }

}