银行管理系统之Java语言实现3

系统需求：

BankSysterm3相对于BankSysterm2提出的新需求有：

1：存储上次变更余额的日期。

2：报告系统运行中发生的错误，例如当取款金额大于余额时提示余额不足

系统设计：

为了适应系统提出的新需求，在设计方面新增了一个Date类，以及在SavingsAccount中加一个error(){} 方法，来实现新的需求。

根据系统代码画出uml类图：

SavingsAccount

-id :string - balance: double          - rate :double - accumulation : double - total : static double -record( Date date , double amount , String desc): void -error(string msg): void - accumulate(Date date): void

+SavingsAccount( Date date, String id, double rate) +getId():String +getBalance() :double + getRate() :double +getTotal() :static double +deposit( Date date, double amount, String desc):void +withdraw(Date date, double amount, String desc):void + settle( Date date):void + show() :void

                                         

 

Date

- year: int    - month : int     - day :int -totalDays :int

+Date(int year, int month, int day) +getYear() :int +getMonth() :int + getDay() :int +getMaxDay() :int +isLeapYear() :int +show() :void + distance( Date date) :int

package Account;
import date.*;

public class SavingsAccount {
		private String id;		//帐号
		private double balance;		//余额
		private double rate;		//存款的年利率
		private Date lastDate;		//上次变更余额的时期
		private double accumulation;	//余额按日累加之和
		private static double total;	//所有账户的总金额

		//记录一笔帐，date为日期，amount为金额，desc为说明
		private void record( Date date, double amount, String desc)
		{
			accumulation = accumulate(date);
			lastDate = date;
			amount = (amount * 100 + 0.5)/ 100;	//保留小数点后两位
			balance += amount;
			total += amount;
			date.show();
			System.out.println("\t#" +id +"\t" + amount + "\t" + balance + "\t" + desc);
		}
		//报告错误信息
		private void error(String msg)
		{
			System.out.println( "Error(#" + id +"): " + msg);
		}
		//获得到指定日期为止的存款金额按日累积值
		private double accumulate(Date date)  {
			return accumulation + balance * date.distance(lastDate);
		}
		//构造函数
		public SavingsAccount( Date date, String id, double rate){
			this.id=id;
			balance=0;
			this.rate=rate;
			this.lastDate=date;
			accumulation=0;
			date.show();
			System.out.println("\t#" + id + " created" );
		}
		public String getId()  { return id; }
		public double getBalance() { return balance; }
		public double getRate()  { return rate; }
		public static double getTotal(){return total;}

		//存入现金
		public void deposit(Date date, double amount, String desc){
			record(date, amount, desc);
		}
		//取出现金
		public void withdraw( Date date, double amount, String desc) {
			if (amount > getBalance())
				error("not enough money");
			else
				record(date, -amount, desc);
		}
		//结算利息，每年1月1日调用一次该函数
		public void settle(Date date){
			double interest = accumulate(date) * rate	//计算年息
					/ date.distance(new Date(date.getYear() - 1, 1, 1));
				if (interest != 0)
					record(date, interest, "interest");
				accumulation = 0;
		}
		
		//显示账户信息
		public void show() {
			System.out.print( id + "\tBalance: " + balance);
		}

}

package Account;
import date.*;

public class SavingsAccount {
		private String id;		//帐号
		private double balance;		//余额
		private double rate;		//存款的年利率
		private Date lastDate;		//上次变更余额的时期
		private double accumulation;	//余额按日累加之和
		private static double total;	//所有账户的总金额

		//记录一笔帐，date为日期，amount为金额，desc为说明
		private void record( Date date, double amount, String desc)
		{
			accumulation = accumulate(date);
			lastDate = date;
			amount = (amount * 100 + 0.5)/ 100;	//保留小数点后两位
			balance += amount;
			total += amount;
			date.show();
			System.out.println("\t#" +id +"\t" + amount + "\t" + balance + "\t" + desc);
		}
		//报告错误信息
		private void error(String msg)
		{
			System.out.println( "Error(#" + id +"): " + msg);
		}
		//获得到指定日期为止的存款金额按日累积值
		private double accumulate(Date date)  {
			return accumulation + balance * date.distance(lastDate);
		}
		//构造函数
		public SavingsAccount( Date date, String id, double rate){
			this.id=id;
			balance=0;
			this.rate=rate;
			this.lastDate=date;
			accumulation=0;
			date.show();
			System.out.println("\t#" + id + " created" );
		}
		public String getId()  { return id; }
		public double getBalance() { return balance; }
		public double getRate()  { return rate; }
		public static double getTotal(){return total;}

		//存入现金
		public void deposit(Date date, double amount, String desc){
			record(date, amount, desc);
		}
		//取出现金
		public void withdraw( Date date, double amount, String desc) {
			if (amount > getBalance())
				error("not enough money");
			else
				record(date, -amount, desc);
		}
		//结算利息，每年1月1日调用一次该函数
		public void settle(Date date){
			double interest = accumulate(date) * rate	//计算年息
					/ date.distance(new Date(date.getYear() - 1, 1, 1));
				if (interest != 0)
					record(date, interest, "interest");
				accumulation = 0;
		}
		
		//显示账户信息
		public void show() {
			System.out.print( id + "\tBalance: " + balance);
		}

}

package bank;
import date.*;
import Account.*;

public class BankSystem {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Date date=new Date(2008, 11, 1);	//起始日期
		//建立几个账户
		SavingsAccount accounts[] = {
			new SavingsAccount(date, "S3755217", 0.015),
			new SavingsAccount(date, "02342342", 0.015)
		};
		final int n = 2; //账户总数
		//11月份的几笔账目
		accounts[0].deposit(new Date(2008, 11, 5), 5000, "salary");
		accounts[1].deposit(new Date(2008, 11, 25), 10000, "sell stock 0323");
		//12月份的几笔账目
		accounts[0].deposit(new Date(2008, 12, 5), 5500, "salary");
		accounts[1].withdraw(new Date(2008, 12, 20), 4000, "buy a laptop");

		//结算所有账户并输出各个账户信息
		System.out.println(" ");
		for (int i = 0; i < n; i++) {
			accounts[i].settle(new Date(2009, 1, 1));
			accounts[i].show();
			System.out.println(" ");
		}
		System.out.println( "Total: " + SavingsAccount.getTotal());
	}

}