我有 2 個類，即 MyClient 和 CustomerUserInterface。MyClient 類有一個 main 方法，我在其中調(diào)用 CustomerUserInterface 的方法。我的客戶    public class MyClient {        public static void main(String args[]) {    CustomerUserInterface customerUserInterface = new CustomerUserInterfaceImpl();    Scanner scan = new Scanner(System.in);    customerUserInterface.registerLoginMenu();    int choice = scan.nextInt();    customerUserInterface.performOperationsOnRegisterLoginMenu(choice);        }    }客戶用戶界面public class CustomerUserInterfaceImpl implements CustomerUserInterface {private CustomerBL customerBl;private ProductInterface productInterface;public CustomerUserInterfaceImpl() {    customerBl = new CustomerBLImpl();    productInterface = new ProductInterfaceImpl();}@Overridepublic void registerLoginMenu() {    System.out.println("1. Register");    System.out.println("2. Login");    System.out.println("3. Exit");}@Overridepublic void register() {    Customer customer = CustomerInputHelper.inputCustomer();    boolean status=false;    try {        status = customerBl.registerUser(customer);    }catch (SQLException e) {        e.printStackTrace();    }    if(status) {        System.out.println("Register Success");        login();    }    else {        System.out.println("Register Unsuccessful");        registerLoginMenu();    }}我面臨的問題是，在第一個 System.out 行之后，我在 login() 方法中遇到錯誤，即Exception in thread "main" java.util.NoSuchElementExceptionat java.util.Scanner.throwFor(Unknown Source)at java.util.Scanner.next(Unknown Source)at java.util.Scanner.nextInt(Unknown Source)at java.util.Scanner.nextInt(Unknown Source)注冊成功后，寄存器會調(diào)用登錄方法，但在登錄方法調(diào)用之后，我收到上述錯誤。我不明白這個問題，因為用戶注冊了，但在調(diào)用登錄方法后立即顯示錯誤。