Android SharedPreferences是否已清除？

Question

I'm using shared preferences as I always do, but recently in a new application the cache suddenly returns null,

here are the methods for read/write

public static void saveToSharedPreferences(Context mContext, String key, String value) {
    if (mContext != null) {
        SharedPreferences mSharedPreferences = mContext.getSharedPreferences(Constants.SHARED_PREFERENCES_NAME, 0);
        if (mSharedPreferences != null)
            mSharedPreferences.edit().putString(key, value).commit();
    }
}

public static String readFromSharedPreferences(Context mContext, String key) {      
    if (mContext != null) {
        SharedPreferences mSharedPreferences = mContext.getSharedPreferences(Constants.SHARED_PREFERENCES_NAME, 0);

        if (mSharedPreferences != null)
            return mSharedPreferences.getString(key, null);
    }
    return null;
}

then in the code

Utils.saveToSharedPreferences(getActivity(), mKey, mDATA);

in the same session when using

String mDATA = Utils.readFromSharedPreferences(getActivity(), mKey);

it does return the value, but later on when exiting the app and lauching it again, it returns null, everything seems to be fine

any help would be appreciated

Answer 1

Are you sure the Context you're using is not NULL? Try this:

SharedPreferences.Editor editor = mSharedPreferences.edit(); 
editor.putString(key, value); 
editor.commit();