练习2

练习目标－使用引用类型的成员变量：在本练习中，将扩展银行项目，添加一个（客户类）Customer类。Customer类将包含一个Account对象。

任务

1.在banking包下的创建Customer类。该类必须实现上面的UML图表中的模型。

a. 声明三个私有对象属性：firstName、lastName和account。

b. 声明一个公有构造器，这个构造器带有两个代表对象属性的参数（f和l）

c. 声明两个公有存取器来访问该对象属性，方法getFirstName和getLastName返回相应的属性。

d. 声明setAccount 方法来对account属性赋值。

e. 声明getAccount 方法以获取account属性。

2.在exercise2主目录里，编译运行这个TestBanking程序。应该看到如下输出结果:

Creating the customer Jane Smith.

Creating her account with a 500.00 balance.

Withdraw 150.00

Deposit 22.50

Withdraw 47.62

Customer [Smith, Jane] has a balance of 324.88

//Customer类

package banking;

public class Customer {

private String firstName,lastName;

private Account account;

public Customer(String f,String l)

{

firstName=f;

lastName=l;

System.out.println("Creating the customer "+f+" "+l);

}

public Account getAccount() {

return account;

}

public void setAccount(Account account) {

this.account = account;

}public String getFirstName() {    return firstName;}public String getLastName() {    return lastName;}

}

//Testbanking类

package banking;

public class TestBanking {

public static void main(String[] args) {    Account a=new Account(500.00);    System.out.println("Creating an account with a "+a.getBalance()+"balance");    a.withdraw(150.00);    a.deposit(22.50);    a.withdraw(47.62);    System.out.println("The account has a balance of "+a.getBalance());    Customer c=new Customer("Jane", "Smith");    Account b=new Account(500.00);    c.setAccount(b);    a=c.getAccount();    System.out.println("Creating her account with a "+a.getBalance()+"balance");    a.withdraw(150.00);    a.deposit(22.50);    a.withdraw(47.62);    System.out.println("Customer ["+c.getFirstName()+","+c.getLastName()+"] has a balance of  "+a.getBalance());    }

}

//运行结果

Creating an account with a 500.0balance

Withdraw 150.0

Deposit 22.5

Withdraw 47.62

The account has a balance of 324.88

Creating the customer Jane Smith

Creating her account with a 500.0balance

Withdraw 150.0

Deposit 22.5

Withdraw 47.62

Customer [Jane,Smith] has a balance of 324.88