如何使用用户输入创建银行账户？

Question

我在项目中有以下课程：

• 账户
• 客户
• 名称：fName和lName（都是字符串字段）
• 日期：年、月、日（均为整数字段）
• 银行：包含账户收款
• InputReader：从键盘读取输入

账户对象需要客户对象和期初余额。客户对象需要名称对象和日期对象。Name对象需要名字和姓氏的字符串我需要向用户询问创建Name和Date对象的详细信息，以及期初余额。

我必须通过从用户那里获取相关信息来创建一个新帐户，即它要求用户输入客户的姓名、出生日期等。它读取用户的回复，创建帐户并将其添加到银行。

当我运行public void createNewAccount（）方法时，我一直收到一条错误消息，上面写着“java.lang.NullPointerException”。非常感谢您的帮助。提前谢谢。

下面是我的银行类源代码。

import java.util.ArrayList;

public class Bank
{
    public static final double INTEREST_RATE = 0.012;//1.2%
    // instance variables - replace the example below with your own
    private ArrayList<Account> accounts;
    private InputReader reader;
    private Name fullName;
    private Date dateOfBirth;

    /**
     * Constructor for objects of class Bank
     */
    public Bank()
    {
        // initialise instance variables

    }

    /*
     * Adds an existing Account to the bank
     * @param account
     */
    public void addAccount(Account account)
    {
        accounts.add(account);
    }

       public void createNewAccount() { 

        System.out.println("Please enter your first name: ");
        String firstName = reader.readString();

        System.out.println("Hello " + firstName + ". " + "What is your last name?");
        String lastName = reader.readString();
        System.out.println("Your last name is " + lastName);


        System.out.println("Please enter your year of birth: ");
        int thisYear = reader.readInt();

        System.out.println("Please enter your month of birth: ");
        int thisMonth = reader.readInt();

        System.out.println("Please enter your date of birth: ");
        int thisDay = reader.readInt();

        Name theName = new Name(firstName, lastName);
        Date theDateOfBirth = new Date(thisYear, thisMonth, thisDay);

    }


}

Answer 1

Scanner scanner = new Scanner(System.in);

The scanner object has a lot of functions you can use;

Answer 2

你可以用扫描仪更换阅读器。差不多吧。

    Scanner scan = new Scanner(System.in);
    System.out.println("Please enter your first name: ");
    String firstName = scan.next();

    System.out.println("Hello " + firstName + ". " + "What is your last name?");
    String lastName = scan.next();
    System.out.println("Your last name is " + lastName);


    System.out.println("Please enter your year of birth: ");
    int thisYear = scan.nextInt();

    System.out.println("Please enter your month of birth: ");
    int thisMonth = scan.nextInt();

    System.out.println("Please enter your date of birth: ");
    int thisDay = scan.nextInt();

  //Then do what you are supposed to do......

Answer 3

您必须先初始化阅读器，然后才能尝试从中读取。