Write an application that displays a series of at least eight student id numbers (that you have stored in an array) and asks the user to enter a test letter grade for the student. create an exception class named gradeexception that contains a static public array of valid grade letters (a, b, c, d, f, and i) that you can use to determine whether a grade entered from the application is valid. in your application, throw a gradeexception if the user does not enter a valid letter grade. catch the gradeexception, and then display the message invalid grade. in addition, store an i (for incomplete) for any student for whom an exception is caught. at the end of the application, display all the student ids and grades.