look

        try {
if(RingtoneManager.getActualDefaultRingtoneUri(context, RingtoneManager.TYPE_RINGTONE).toString().trim().equals("")||
RingtoneManager.getActualDefaultRingtoneUri(context, RingtoneManager.TYPE_RINGTONE).toString()==null){
RingtoneManager.setActualDefaultRingtoneUri(context, RingtoneManager.TYPE_RINGTONE, Settings.System.DEFAULT_RINGTONE_URI);
}
} catch (Exception e1) {
Log.e(TAG+"  aaa  ", e1.getMessage());
}