个人银行账户管理程序剖析

个人银行账户管理程序

实验内容：

设计一个程序，实现对个人银行账户的管理。银行账户有储蓄账户和信用账户两类。储蓄账户不可以透支，利息每年结算一次；信用账户允许在一定额度内透支，透支则需支付利息，并在每月1日进行一次结算。

实验要求：

1.程序要实现的功能：

a)用户创建新账户需要提供基本的账号以及金额，如果是储蓄账户，还需

定义年利率，如果是信用账户，则还需定义信用额度，日利率，年费

b)储蓄账户：在每年的1月1日结算利息，利息的计算: 将一年中每天的

余额累积起来再除以一年总天数，得到日均余额，再乘以年利率

c)信用账户：在每年的1月1日扣取年费，信用账户没有利息，但透支则

需要支付利息，从透支那天开始计算利息(日均欠费金额×利率)，并在

每月的1日进行一次结算

d)用户能查看账户信息以及账户余额的变动情况

e)用户存取款需要提供日期和金额，取款失败应提示输出失败原因

2.设计类并写出每个类的详细描述(包括构造函数，成员变量，成员函数的含义)

和画出UML类图(体现类之间的关系和类内成员的访问权限)

3.程序中使用的类应该做到类定义和实现分离(使用多文件结构)

4.设计测试用例对程序功能进行充分测试，并对运行结果进行截图

实验分析：

定义账户基类Account描述所有账户的共性，包含私有成员：账号id、余额balance、账户总金额静态数据成员total；保护成员：构造函数Account()、记账函数record()、错误信息报告常函数error()；公有成员：获取账号常函数getId()、获取余额常函数getBalance()、获取总金额静态函数getTotal()、显示账户信息show()。

再从账户基类中公有派生出储蓄账户类SavingsAccount和信用账户类CreditAccount，储蓄类账户中定义了私有成员：辅助计算利息的累加器acc、存款的年利率rate，公有成员：构造函数SavingsAccount()、用于访问年利率的常函数getRate()、存现金函数deposit()、取现金函数withdraw()、利息结算函数settle()。信用类账户中定义了私有成员：辅助计算利息的累加器acc、信用额度credit、欠款的日利率rate、信用卡年费fee、获得欠款项函数getDebt()；公有成员：构造函数CreditAccount()、获取信用额度常函数getCredit()、获取日利率常函数getRate()、获取年费常函数getFee()、获得可用信用额度常函数getAvailableCredit()、存现金函数deposit()、取现金函数withdraw()、利息和年费结算函数settle()。

定义类Accumulator，用于计算一项数值的按日累加之和的接口，通过该类计算利息，包含三个数据成员——表示被累加数值上次变更日期的lastDate、被累加数值当前值value以及上次变更被累加数值为止的按日累加总和sum，该类

同时包含四个函数成员——构造函数Accumulator()、用来计算到指定日期的累加结果的常函数getSum()、用来在指定日期更改数值的函数change()以及用来将累加器清零并重新设定初始日期和数值的函数reset()。

定义日期类Date ，该类的数据成员包含year 、month 、day 和totalDays ，其中totalDays 表示这一天的相对日期。该类的成员函数除了构造函数和用来获得year 、month 、day 的函数外，还包括用来得到当前月的天数getMaxDay()函数、用来判断当前年是否为闰年的isLeapYear()函数、用来将当前日期输出的show()函数、用来判断当前日期与指定日期相差天数的distance()函数，这些函数都会被Date 类的其他成员函数或SavingsAccount 类的函数调用。

以上各个类之间的UML 类图如下：

+Date(in year : int, in month : int, in day : int)

<> +getYear() : int

<> +getMonth() : int

<> +getDay() : int

<> +getMaxDay() : int

<> +isLeapTear() : bool

<> +show()

<> +distance(in date : Date) : int -year : int

-month : int

-day : int

-totalDays : int

Date

#Account(in date : Date, in id : int)#record(in date : Date, in amount : double, in desc : string)<> #error(in msg : string)<> +getId() : int <> +getBalance() : double <> +show()<> +getTotal() : double

-id : string -balance : double -total : double Account <> -getDedt() : double

+CreditAccount(in date : Date, in id : int, in credit : double, in rate : double, in fee : double)

<> +getCredit() : double

<> +getRate() : double

<> +getFee() : double

<> +getAvailableCredit() : double

+deposit(in date : Date, in amount : double, in desc : string)

+withdraw(in date : Date, in amount : double, in desc : string)

+settle(in date : Date)

<> +show()

-acc : Accumulator

-credit : double

-rate : double

-fee : double

CreditAccount

+Accumulator(in date : Date, in value : double)

<> +getSum(in date : Date) : double

+change(in date : Date, in value : double)

+reset(in date : Date, in value : double)-lastDate : Date

-value : double

-sum : double

Accumulator

+SavingsAccount(in date : Date, in id : int, in rate : double)<> +getRate() : double +deposit(in date : Date, in amount : double, in desc : string)+withdraw(in date : Date, in amount : double, in desc : string)+settle(in date : Date)

-acc : Accumulator -rate : double SavingsAccount 1

1

1

程序代码：

账户类定义头文件：

//Account.h

#ifndef _ACCOUNT_H_

#define _ACCOUNT_H_

#include

#include "Date.h"

#include "Accumulator.h"

class Account {

private:

std::string id;

double balance;

static double total;

protected:

Account(const Date &date, const std::string &id);

void record(const Date &date, double amount, const std::string &desc);

void error(const Date &date, double amount, const std::string &msg) const;

public:

const std::string &getId() const{

return id;

}

double getBalance() const{

return balance;

}

static double getTotal(){

return total;

}

void show() const;

};

class SavingsAccount:public Account {

private:

Accumulator acc;

double rate;

public:

SavingsAccount(const Date &date, const std::string &id, double rate);

double getRate() const {

return rate;

void deposit(const Date &date, double amount, const std::string &desc);

void withdraw(const Date &date, double amount, const

std::string &desc);

void settle(const Date &date);

};

class CreditAccount:public Account{

private:

Accumulator acc;

double credit;

double rate;

double fee;

double getDebt() const {

double balance = getBalance();

return (balance<0 ? balance : 0);

}

public:

CreditAccount(const Date &date, const std::string &id, double credit, double rate, double fee);

double getCredit() const {

return credit;

}

double getRate() const{

return rate;

}

double getFee(){

return fee;

}

double getAvailableCredit() const{

if(getBalance() < 0)

return credit + getBalance();

else

return credit;

}

void deposit(const Date &date, double amount, const std::string &desc);

void withdraw(const Date &date, double amount, const

std::string &desc);

void settle(const Date &date);

void show() const;

};

账户类实现文件：

//Account.cpp

#include

#include

#include

#include "Account.h"

using namespace std;

double Account::total = 0;

Account::Account(const Date &date, const std::string &id):id(id), balance(0){

date.show();

cout << "\t#" << id << " is created" << endl;

}

void Account::record(const Date &date, double amount, const std::string &desc){

amount = floor(amount * 100 + 0.5) / 100;

balance += amount;

total += amount;

date.show();

cout << "\t#" << id << "\t" << setw(6) << amount << "\t" << setw(10) << balance << "\t" << desc << endl;

}

void Account::show() const{

cout << "#" << id << "\tBalance:" << balance;

}

void Account::error(const Date &date, double amount, const string &msg) const{

date.show();

cout<< "\t#" << id << "\t" << setw(6) << amount << "\t" << setw(10) << balance << "\t" << "Error:"+msg <

}

SavingsAccount::SavingsAccount(const Date &date, const

std::string &id, double

rate):Account(date,id),rate(rate),acc(date,0) {}

void SavingsAccount::deposit(const Date &date, double amount, const string &desc) {

record(date,amount,desc);

acc.change(date,getBalance());

void SavingsAccount::withdraw(const Date &date, double amount, const string &desc){

if(amount>getBalance()){

error(date, amount, "you not enough money");

} else {

record(date,-amount,desc);

acc.change(date,getBalance());

}

}

void SavingsAccount::settle(const Date &date){

double interest = acc.getSum(date) * rate /

date.distance( Date(date.getYear()-1,1,1) );

if(interest!=0){

record(date,interest,"interest");

}

acc.reset(date,getBalance());

}

CreditAccount::CreditAccount(const Date &date,const string& id,double credit,double rate,double

fee):Account(date,id),credit(credit),rate(rate),fee(fee),acc(d ate,0){}

void CreditAccount::deposit(const Date &date,double amount,const string &desc){

record(date,amount,desc);

acc.change(date,getDebt());

}

void CreditAccount::withdraw(const Date &date,double amount,const string &desc){

if(amount-getBalance()>credit){

error(date, amount, "you not enough credit");

} else{

record(date,-amount,desc);

acc.change(date,getDebt());

}

}

void CreditAccount::settle(const Date &date){

double interest=acc.getSum(date)*rate;

if(interest!=0){

record(date,interest,"interest");

}

if(date.getMonth()==1){

record(date,-fee,"annual fee");

acc.reset(date,getDebt());

}

void CreditAccount::show() const{

Account::show();

cout << "\t\tAvailable credit:" << getAvailableCredit(); }

日期类头文件：

//Date.h

#ifndef _DATE_H_

#define _DATE_H_

class Date {

private:

int year;

int month;

int day;

int totalDays;

public:

Date(int year, int month, int day);

int getYear() const {

return year;

}

int getMonth() const {

return month;

}

int getDay() const {

return day;

}

int getMaxDay() const;

bool isLeapYear() const {

return year%4==0 && year%100!=0 || year%400==0;

}

int distance(const Date& date) const {

return totalDays - date.totalDays;

}

void show() const;

};

#endif

日期类实现文件：

//Date.cpp

#include

#include

#include "Date.h"

using namespace std;

namespace {

const int

DAYS_BEFORE_MONTH[]={0,31,59,90,120,151,181,212,243,273,304,33 4,365};

}

Date::Date(int year,int month,int

day):year(year),month(month),day(day) {

if(day <= 0 || day > getMaxDay()) {

cout << "Invalid date: ";

show();

cout << endl;

exit(1);

}

int years = year - 1;

totalDays = years*365 + years/4 - years/100 + years/400 + DAYS_BEFORE_MONTH[month-1] + day;

if(isLeapYear() && month > 2)

totalDays++;

}

int Date::getMaxDay() const {

if(isLeapYear() && month == 2)

return 29;

else

return DAYS_BEFORE_MONTH[month] -

DAYS_BEFORE_MONTH[month-1];

}

void Date::show() const {

cout << getYear() << "-" << getMonth() << "-" << getDay(); }

Accumulator类头文件：

//Accumulator.h

#ifndef _ACCUMULATOR_H_

#define _ACCUMULATOR_H_

#include "Date.h"

class Accumulator{

private:

Date lastDate;

double value;

double sum;

public:

Accumulator(const Date &date, double value):lastDate(date), value(value), sum(0){}

double getSum(const Date &date) const {

return sum + value*date.distance(lastDate);

}

void change(const Date &date, double value) {

sum = getSum(date);

lastDate = date;

this->value = value;

}

void reset(const Date &date, double value) {

lastDate = date;

this->value = value;

sum=0;

}

};

#endif

测试用例及截图：

//main.cpp

#include

#include

#include "Account.h"

using namespace std;

int main() {

Date date(2016, 12, 22);

cout<<"建立账户"<

SavingsAccount sa1(date, "SA_2016", 0.015);

SavingsAccount sa2(date, "SA_2017", 0.015);

CreditAccount ca(date, "CA_2018", 10000, 0.0005, 100);

cout<<"所有账户的交易记录(存款、取款、结算)"<

cout<<"Time\t\t"<<"Account_id\t"<

sa1.settle(Date(2017, 1, 1));

sa2.settle(Date(2017, 1, 1));

ca.settle(Date(2017, 1, 1));

sa1.deposit(Date(2017, 1, 5), 5000, "salary");

ca.withdraw(Date(2017, 1, 15), 3000, "buy a cell");

sa2.deposit(Date(2017, 1, 25), 10000, "sell stock 0323");

ca.settle(Date(2017, 2, 1));

ca.settle(Date(2017, 3, 1));

ca.settle(Date(2017, 4, 1));

ca.deposit(Date(2017, 4, 1), 2018, "repay the credit");

ca.settle(Date(2017, 5, 1));

sa1.deposit(Date(2017, 5, 5), 5500, "salary");

ca.settle(Date(2017, 6, 1));

ca.settle(Date(2017, 7, 1));

ca.withdraw(Date(2017, 7, 10), 10000, "donation");

sa2.withdraw(Date(2017, 7, 20), 15000, "buy a cell phone");

ca.settle(Date(2017, 8, 1));

ca.deposit(Date(2017, 8, 26), 1000, "repay the credit");

ca.settle(Date(2017, 9, 1));

ca.settle(Date(2017, 10, 1));

ca.settle(Date(2017, 11, 1));

ca.settle(Date(2017, 12, 1));

sa1.settle(Date(2018, 1, 1));

sa2.settle(Date(2018, 1, 1));

ca.settle(Date(2018, 1, 1));

cout<<"所有账户信息"<

sa1.show();cout<

sa2.show();cout<

ca.show();cout<

cout<<"所有账户总金额Total："<< Account::getTotal() <

return 0;

}

运行结果：