我在java中制作银行程序并有5个类： 帐户，SavingsAccount（继承帐户），CreditAccount（继承帐户），银行，客户。
该计划正在按原样运作，但我无法弄清楚如何让客户拥有两个或更多帐户。假设一个客户想要一个信用账户和一个储蓄账户，或者两个储蓄账户。
有人能给我一些建议吗？谢谢
银行类：
public class Bank {
String bankName;
private Customer[] customers = new Customer[100];
Bank(String bankName) {
this.bankName = bankName;
}
public Customer[] getCustomer() {
return customers;
}
public String getBankname() {
return bankName;
}
}
帐户类：
public abstract class Account {
protected double balance = 0;
protected String accountId;
public Account() {} //Defaultkonstruktor
public Account(double bal, String id) { //Konstruktor
if (balance >= 0) {
balance = bal;
}
else {
balance = 0;
}
accountId = id;
}
public abstract void deposit(double amount);
public abstract void withdraw(double amount);
public abstract double getBalance();
public abstract String getAccountId();
public abstract void transfer(double amount, Account account);
}
SavingsAccount类:( CreditAccount类类似）
public class SavingsAccount extends Account{
private double interest = 2.9;
public SavingsAccount() { //Konstruktor
super();
}
public SavingsAccount(double balance, String id) { //Konstruktor
super(bal,id);
}
public void setInterest(Customer customer) {
//code
}
public void setBalance(double balance) {
//code
}
@Override
public void deposit(double amount) {
//code
}
@Override
public void withdraw(double amount) {
//code
}
@Override
public double getBalance(){
//code
}
@Override
public String getAccountId(){
//code
}
@Override
public void transfer(double amount, Account account) {
//code
}
public void setInterest(double interest){
//code
}
public double getInterest(){
//code
}
}
客户类：
public class Customer {
private String firstName;
private String lastName;
private String number;
private SavingsAccount account = new SavingsAccount();
private CreditAccount cAccount = new CreditAccount();
Customer(String firstName, String lastName, String number, SavingsAccount account) {
this.firstName = firstName;
this.lastName = lastName;
this.number = number;
this.account = account;
}
Customer(String firstName, String lastName, String number, CreditAccount cAccount) {
this.firstName = firstName;
this.lastName = lastName;
this.number = number;
this.cAccount = cAccount;
}
public SavingsAccount getAccount() {
return account;
}
public CreditAccount getCreditAccount() {
return cAccount;
}
}
主：
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int choice;
int numberOfCustomers = 0;
boolean endProgram = false;
String bankName;
System.out.print("Name of bank: ");
bankName = input.next();
Bank bank = new Bank(bankName);
String accountId;
SavingsAccount acc = new SavingsAccount();
Customer[] customer = bank.getCustomer();
do {
System.out.println(" " + bank.getBankname() + "\n");
System.out.println(" 1. See balance ");
System.out.println(" 2. Withdraw ");
System.out.println(" 3. Deposit ");
System.out.println(" 4. Transfer ");
System.out.println(" 5. Add interest ");
System.out.println(" 6. Add new customer ");
System.out.println(" 7. Show customers ");
System.out.println(" 8. Change interest ");
System.out.println(" 0. Exit ");
choice = input.nextInt();
switch(choice) {
case 1:
//code
break;
case 2:
//code
break;
case 3:
//code
break;
case 4:
//code
break;
case 5:
//code
break;
case 6: //Add customer
System.out.println("Choose account: ");
System.out.println("1. Savings account");
System.out.println("2. Credit account");
choice = input.nextInt();
switch(choice) {
case 1: //Create savings account
System.out.print("Enter amount to deposit: ");
double amount = input.nextDouble();
System.out.println("Account number is: " + numberOfCustomers);
SavingsAccount savingsAccount = new SavingsAccount(amount, String.valueOf(numberOfCustomers));
System.out.print("First name: ");
String firstName = input.next();
System.out.print("Last name: ");
String lastName = input.next();
System.out.print("Customer number: ");
String pnumber = input.next();
Customer newCustomer = new Customer(firstName, lastName, pnumber, savingsAccount);
customer[numberOfCustomers] = newCustomer;
numberOfCustomers++;
break;
case 2: //Create credit account
System.out.print("Enter amount to deposit: ");
double amount = input.nextDouble();
System.out.println("Account number is: " + numberOfCustomers);
CreditAccount creditAccount = new CreditAccount(amount, String.valueOf(numberOfCustomers));
System.out.print("First name: ");
String firstName = input.next();
System.out.print("Last name: ");
String lastName = input.next();
System.out.print("Customer number: ");
String pnumber = input.next();
Customer newCustomer = new Customer(firstName, lastName, pnumber, creditAccount);
customer[numberOfCustomers] = newCustomer;
numberOfCustomers++;
break;
}
break;
case 7:
//code
break;
case 8:
//code
break;
case 0:
//code
break;
}
} while (!endProgram);
}
答案 0 :(得分：6)
首先将Account重命名为AbstractAccount并创建一个Account接口，您的Credit和Saving帐户是具体实现。然后在您的Customer类中声明一个变量帐户，这是一个List帐户。像
这样的东西public class Customer {
private String firstName;
private String lastName;
private String number;
private List<Account> accounts;
您的帐户界面可能如
interface Account {
public void deposit(double amount);
public void withdraw(double amount);
public double getBalance();
public String getAccountId();
}
您现有的课程被重构
public abstract AbstractAccount implements Account {
....
}
您的SavingAccount变为
public SavingAccount extends AbstractAccount {
....
}
我有点担心这个方法在Account类上被声明为abstract。为什么转移会在两个不同的类别上以不同的方式实现？
public abstract void transfer(double amount, Account account);
我建议这种方法更多地属于AccountManager类，这样可以确保从两个帐户中记入/记入正确的金额。
public void transfer(double amount, Account fromAccount, Account toAccount);
然后，该类可以检查'fromAccount'是否具有可用于在实际转移发生之前作为验证步骤进行转移的资金。
答案 1 :(得分：1)
而不是访问客户的对象构造函数SavingsAccount或CreditAccount， 你可以使用：
Customer(String firstName, String lastName, String number) {
...
}
并将set方法添加到帐户和cAccount：
Public void setAccount(SavingAccount account) {
This.account = account;
}
当然你可以像上一条评论一样创建一个列表：
并添加方法：
public void addAccount(Account account) {
accounts.add(account);
}