從ArrayList獲取特定元素

Question

我主要是這樣做的：首先，我用名字，姓氏和號碼創建一個新客戶。 然后，我創建兩個SavingsAccounts，分別為其金額，id和利率。 然后，我將兩個SavingsAccounts添加到新客戶。 最后，我將新客戶添加到銀行。

Customer newCustomer = new Customer(firstName, lastName, pnumber);    

SavingsAccount savingsAccount1 = new SavingsAccount(400, "1", 4); //400$ into account no.1, with interest 4%
SavingsAccount savingsAccount2 = new SavingsAccount(300, "2", 3);

newCustomer.addAccount(savingsAccount1);  
newCustomer.addAccount(savingsAccount2);  

bank.addCustomer(newCustomer); 

這是班級銀行：

public class Bank {
    String bankName;    
    private ArrayList<Customer> customers = new ArrayList<Customer>(); 

    Bank(String bankName) {
        this.bankName = bankName;
    }

    public void addCustomer(Customer newCustomer) {
        customers.add(newCustomer);
    }
}

這是類客戶：

public class Customer {
    private String firstName;
    private String lastName;
    private String number;      
    private ArrayList<Account> accounts;

    Customer(String firstName, String lastName, String number) { 
        this.firstName = firstName;
        this.lastName = lastName;
        this.number = number;
        this.accounts = new ArrayList<Account>();
    }

    public void addAccount(SavingsAccount account) {
        accounts.add(account);
    }

    public void addAccount(CreditAccount account) {
        accounts.add(account);
    }

    public ArrayList<Account> getAccounts() {
        return accounts;
    }
}

這是SavingsAccount類（繼承了Account類）：

public class SavingsAccount extends Account {

    public SavingsAccount() {     
        super();
    }

    public SavingsAccount(double bal, String id, double inte) {   
       super(bal, id, inte);
    }

    @Override
    public void deposit(String number, String id, double amount) {

    }

    @Override
    public void withdraw(String number, String id, double amount) {

    }

    @Override
    public void transfer(String number, String id, double amount) {

   }

    @Override  
    public double getBalance() {

    }

    @Override
    public String getAccountId() {
        return accountId;
    }

    @Override
    public double getInterest(){
        return interest;
    }
}

我的問題是：如何在SavingsAccount類中編寫代碼以為特定客戶和特定帳戶存入，提取或轉賬？ 假設我想向1號客戶的2號客戶存款500。

那應該是諸如SavingsAccount.deposit（“ 2”，“ 1”，500）;之類的東西。

我只是不知道如何訪問2號客戶和1號客戶。有人可以幫我嗎？

Answer 1

您可以做的是在Bank類中找到一種方法：

public class Bank {
  // Your stuff
  // new method:
  public boolean transfer(Account accountFrom, double amount, String nameTo, int account) {
     //check if the balance can be deposit from the account
     if(amount <= accountFrom.getBalance()) {
        //Check if the person exists in the bank
        String name = nameTo.split(" "); // name[0] is the first name, name[1] last name

        boolean success = false;
        for(Customer c: customers) {
           if(c.getFirstName().equalsIgnoreCase(name[0]) &&
                     c.getLastName().equalsIgnoreCase(name[1]) {
              for(Account a : c.getAccounts()) {
                 if(a.getAccountId() == account) {
                    // Add it to the account
                    a.deposit(amount);
                    success = true;
                    break;
                 }
              }
              break;
           }
        }

        // Deposit it from the account (That class should only keep track of money, so it 
        // only takes an argument to deposit or withdraw a value, the rest is done by the bank
        // Only do this if money has been dsposited at the target account
        if(success){
          accountFrom.withdraw(amount);
          return true;
        }

     }
     return false;
  }
}

為此，您必須從結構上更改您的設置。

如果帳戶僅管理資金，則這些帳戶將添加到客戶中。 客戶是在銀行與其本人之間進行溝通的人。 最后，銀行與客戶溝通。

希望這對您有幫助