I have an object which represents a phone number. User is adding phone numbers in bulk. In my service layer I am creating those number objects and saving in the Database. But there are few checks that I have to do : for example if number does not start with 700 I have to add that number successfully but I have to show a warning to user about this. Now in the service I am returning count of numbers added successfully and errors in case anything bad happen. I need a way to pass these warnings as well. Can any one suggest me good way to do this or if grails provide anything related to this?