java如何创建菜单控制台循环？

Question

我必须创建一个菜单供用户选择，当用户输入不正确的选项时，我需要它循环。到目前为止我掌握的代码；它会持续循环，或者当我运行程序时，它会给我所有选择的输出，而不是我专门输入的输出。我的循环是一个带有switch语句的do/while循环。我会把我试过的贴在下面。我只需要知道我的循环代码是否正确，如果不正确，如何修复它？如果需要任何澄清，请询问。我很抱歉，如果我听起来真的很懒或愚蠢，我只是想能够理解这一点，有时，我就是不理解，所以请寻求一些额外的帮助

 do
{

int selection = 0;


System.out.println("Please choose one of the following to determine whether you are a new or existing cutomer:");
System.out.println("[1]- Existing Customer");
System.out.println("[2] - New Customer");

System.out.println("Insert selection:");


switch (selection)
{
case 1:
System.out.println("Welcome Back" + userName);
break;

case 2:
System.out.println("Hello, I see you are a new customer,");
System.out.println("let's get your account setup!");
break;

case 3:
default: System.out.println("That is not a vaild. Please select from one of the following options.");
break;
}
while (selection !=3);

Answer 1

         String[] options = new String[]{
           "Existing Customer",
           "New Customer"
         };   

        int selection = 0;

        do{
            System.out.println("Please choose one of the following to determine whether you are a new or existing customer");
            for (int i = 0; i < options.length; i++) {
                System.out.printf("[%s] - %s%n",i+1, options[i]);
            }
            String input = new Scanner(System.in).nextLine();
            try{
                selection = Integer.parseInt(input);
            }catch(NumberFormatException e){
                System.out.println("That is not a vaild. Please select from one of the following options.");
                selection = 0;
            }
        }while(selection <= 0 || selection > options.length);

        switch(selection){
            case 1:
                System.out.println("Welcome Back");
                break;
            case 2:
                System.out.println("Hello, I see you are a new customer,");
                System.out.println("let's get your account setup!");
                break;
        }