shared prefs file doesnt create code example

Example 1: refresh sharedpreferences going back java

getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);

Example 2: set preference value android

boolean committed = PreferenceManager.getDefaultSharedPreferences(yourContext).edit().putBoolean(key, mValue).commit();
//you can also use putInt, putFloat, putLong, putString, putStringSet and change the value of mValue
//committed is true if everything went alright, false if there was an error