Bank4

Account：

package banking4;

public class Account {
    private double balance;

    public Account(double int_balance) {
        balance = int_balance;
    }

    public double getBlance() {
        return balance;
    }

    public boolean deposit(double amt) {
        balance += amt;
        return true;
    }

    public boolean withdraw(double amt) {
        if (balance >= amt) {
            balance -= amt;
            return true;
        } else {
            System.out.println("余额不足");
            return false;
        }
    }
}

Customer：

package banking4;

public class Customer {
    private String firstName;
    private String lastName;
    private Account account;

    public Customer(String f, String l) {
        firstName = f;
        lastName = l;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public Account getAccount() {
        return account;
    }

    public void setAccount(Account acct) {
        account = acct;

    }

}

Bank：

package banking4;

public class Bank {

    private Customer[] customers;// 用于存放客户的
    private int numberOfCustomers;// 记录Customer的个数

    public Bank() {
        customers = new Customer[5];
    }

    // 添加一个Customer到数组中
    public void addCustomer(String f, String l) {
        Customer cust = new Customer(f, l);
        customers[numberOfCustomers] = cust;
        numberOfCustomers++;
    }

    // 获取Customer的个数
    public int getNumberofCustomer() {
        return numberOfCustomers;
    }

    // f返回指定索引位置Customer
    public Customer getCustomer(int index) {
        return customers[index];
    }
}

TestBanking4：

package TestBanking;
/*
 * This class creates the program to test the banking classes.
 * It creates a new Bank, sets the Customer (with an initial balance),
 * and performs a series of transactions with the Account object.
 */

import banking4.*;

public class TestBanking4 {

  public static void main(String[] args) {
    Bank  bank = new Bank();

    // Add Customer Jane, Simms
   bank.addCustomer("Jane", "Simms");
    //code
    //Add Customer Owen, Bryant
   bank.addCustomer("Owen", "Bryant");
    //code
    // Add Customer Tim, Soley
   bank.addCustomer("Tim", "Soley");
    //code
    // Add Customer Maria, Soley
   bank.addCustomer("Maria", "Soley");
    //code
    for ( int i = 0; i < bank.getNumberofCustomer(); i++ ) {
      Customer customer = bank.getCustomer(i);

      System.out.println("Customer [" + (i+1) + "] is "
             + customer.getLastName()
             + ", " + customer.getFirstName());
    }
  }
}

输出结果：

Customer [1] is Simms, Jane
Customer [2] is Bryant, Owen
Customer [3] is Soley, Tim
Customer [4] is Soley, Maria