Create a method print a string If type is not string then throw exceptionand retry 3 times

import java.util.Scanner;
public class MyClass {
    public static void main(String args[]) {
      
      Scanner myObj = new Scanner(System.in);

      System.out.println("Enter username");

      String userName = myObj.nextLine();

      System.out.println("Username is: " + userName);
    }
}