Please solve the problem in JAVA ! Write a class registration where you ask the user for a username and PIN. Use Exception Handling to Handle the following situations. . . Username cannot be blank and should not start with black space. PIN should only contain 5 digits and no more. Write some code to same the Username and input in a file. Also, write a class verification to see if the username and PIN given by the user is valid or not (that is if it exists in the said file)