java - 问题错误检查码

Question

import java.util.*;

public class AccountClient {

public static void main(String[] args)  {
    @SuppressWarnings("resource")
    Scanner input = new Scanner(System.in);
    boolean infiniteLoop = true;
    boolean invalidInput;
    int id = 0;

    // Create array of different accounts
    Account[] accountArray = new Account[1000000];
    //Initialize each account array with its own unique id and a starting account balance of $100
    for (int i = 0; i < accountArray.length; i++) {
        accountArray[i] = new Account("name", i, 100);
    }
    do {    
        try {       
            //inner loop to detect invalid Input
            do {
                invalidInput = false;
                System.out.print("Enter an id: ");

                if (!(input.hasNextInt())) {
                    System.out.println("Invalid input. Please enter a numeric id between 0 and 999999, no letters or symbols allowed. Try again.");
                    invalidInput = true;
                    input.nextLine();
                }


                else {
                    id = input.nextInt(); 
                    accountArray[id].setNumberOfTimesOpened(accountArray[id].getNumberOfTimesOpened() + 1);
                    input.nextLine();
                    if (accountArray[id].firstTimeAccount()) {
                        System.out.print("Please enter a name to register to this account: ");
                        String name = input.nextLine();
                        accountArray[id].setName(name);
                    }
                }

            } while (invalidInput);
            boolean exit;
            do {
                exit = false;
                boolean notAnOption;
                int choice;
                do {
                    notAnOption = false;
                    System.out.print("\nMain Menu\n1: check balance\n2: withdraw\n3: deposit\n4: view transaction history\n5: exit\nEnter a choice: ");
                    choice = input.nextInt();
                    if (choice < 1 || choice > 5) {
                        System.out.println("Sorry, " + choice + " is not an option. Please try again and enter a number between 1 and 5 (inclusive).");
                        notAnOption = true;
                    }
                } while(notAnOption);
                switch (choice) {
                case 1: System.out.printf("The balance for your account is $%.2f\n", accountArray[id].getBalance());
                    break;
                case 2: {
                    boolean withdrawFlag;
                    do {
                        System.out.print("Enter the amount you would like to withdraw: ");
                        double withdrawAmount = input.nextDouble();
                        input.nextLine();
                        if (withdrawAmount > accountArray[id].getBalance()) {     
                            System.out.printf("Sorry, you only have an account balance of $%.2f. Please try again and enter a number at or below this amount.\n", accountArray[id].getBalance());
                            withdrawFlag = true;
                        }
                        else {
                            accountArray[id].withdraw(withdrawAmount);
                            System.out.printf("Thank you. You have successfully withdrawn $%.2f from your account.\n", withdrawAmount);
                            withdrawFlag = false;
                        }
                    } while (withdrawFlag);
                }

                    break;
                case 3: {
                    System.out.print("Enter the amount you would like to deposit: ");
                    double depositAmount = input.nextDouble();
                    input.nextLine();
                    accountArray[id].deposit(depositAmount);
                    System.out.printf("Thank you. You have successfully deposited $%.2f into your account.\n", depositAmount); 
                    }
                    break;
                case 4: {
                    accountArray[id].accountSummary();
                    }
                    break;
                case 5: {
                    System.out.println("returning to the login screen...\n");
                    exit = true;
                    }
                    break;
                }

            } while (exit == false);

        }

        catch (ArrayIndexOutOfBoundsException ex1) {
            System.out.println("Invalid input. Please enter an id between 0 and 999999 (inclusive).");  
            input.nextLine();
        }

        catch (InputMismatchException ex2) {
            System.out.println("Sorry, invalid input. Please enter an id between 0 and 999999 (inclusive) with no letters or symbols.");
            input.nextLine();
        }

    } while (infiniteLoop);

  } 

}

大家好，我有一个模拟ATM机的程序。它使用我创建的帐户类，在用户输入0到999999之间的ID后为用户生成帐户。然后他们可以执行各种任务，例如查看余额，提款，存款等。检查程序。它编译时没有错误，并且在第一次循环时就可以完美运行。但是，如果他们按exit并输入另一个无效ID，它将两次显示无效输入消息。我复制了下面发生的情况的控制台。有人可以向我解释为什么这样做以及如何解决它。我也是Java的新手，所以如果有人可以告诉我一种更好的错误检查方法，将不胜感激。截至目前，如果他们输入一个int值并且它不在0到999999的范围内，我必须有一个单独的ArrayIndexOutofBoundsException来捕获错误。这似乎效率低下。有没有一种方法可以错误检查它们是否输入了数字，是否输入了数值，请再次检查是否输入了0到999999之间的输入？谢谢

输入ID:f

输入无效。请输入介于0到999999之间的数字ID，不允许使用字母或符号。再试一次。

输入ID:5

请输入名称以注册到该帐户:Bob

主菜单

1:检查余额

2:退出

3:存款

4:查看交易记录

5:退出

输入选择:5

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输入ID:f

输入无效。请输入介于0到999999之间的数字ID，不允许使用字母或符号。再试一次。

输入ID:输入无效。请输入介于0到999999之间的数字ID，不允许使用字母或符号。再试一次。

输入ID:

Answer 1

我从任何人那里得到了零帮助，但是经过数小时的挫败之后，我意识到这是因为在我要求用户选择一个选项之后，我无法放入input.nextLine()。这导致扫描器无法清除，并导致语句在开始时在内部循环中被清除之前被打印两次。一旦我添加了input.nextLine()，它就可以正常工作。