how to check the SharedPreferences string is empty or null *android

Question

I want to check a string in SharedPreferences used it to store username and password, so if username and password is not null or empty it will be directed to home, otherwise

Answer 1

 if(appSettings.contains(Constants.WEATHER_SUBN_POSTION)) {
        savedSubPostion = appSettings.getInt(Constants.WEATHER_SUBN_POSTION, 0);
 }

First check it contains the value.