一个面向对象的Java实例:银行账户

//纯面向对象
//银行普通客户类
//取款不可透支,不可转账
public class Cust {

	String name;
	int ID;
	int password;
	int money;

	Cust(String name,int ID,int password,int money)
	{
		this.name=name;
		this.ID=ID;
		this.password=password;
		this.money=money;
	}

	boolean getMoney(int m)
	{
		if(m<0)
			{
			if(saveMoney(-m))
				return true;
			else
				return false;
			}
		else
		{
			if(m>money)
			{
				System.out.println("Warning：该账户不可透支,本次操作中断！");
				return false;
			}
			this.money-=m;
			return true;
		}
	}

	boolean saveMoney(int m)
	{
		if(m<0)
		{
			if(getMoney(-m))
				return true;
			else
				return false;
		}
		else
			{
			this.money+=m;
			return true;
			}
	}

	void search()
	{
		System.out.println(name+"（" + ID +") 余额:"+money);
	}

	boolean checkpw()
	{
		int i;
		for(i=0;i<3;i++)
		{
			if(i>0)
				System.out.println("Warning：密码错误，请输入密码：");
			int pw=KB.scanInt();
			if(pw==password)
				return true;
		}
		if(i==3)
			System.out.println("Warning：密码输入出错3次，操作中断！");
		return false;
	}

	void run(Cust st[])
	{

		while(true)
		{
			printMenu();
			int cmd=KB.scanInt();
			switch(cmd)
			{
			case 1:
			{
				System.out.println("请输入存款数：");
				int m=KB.scanInt();
				saveMoney(m);
				break;
			}
			case 2:
			{
				System.out.println("请输入取款数：");
				int m=KB.scanInt();
				getMoney(m);
				break;
			}
			case 3:
				search();break;
			case 0:return;
			}
		}
	}

	static void printMenu()
	{
		//System.out.println("诚信银行");
		System.out.println("——————");
		System.out.println("存款——1");
		System.out.println("取款——2");
		System.out.println("查余——3");
		System.out.println("退出——0");
		System.out.println("——————");
	}
}

//银行VIP客户类
//取款可透资,可转账
public class CustVip extends Cust
{
	CustVip(String name,int ID,int password,int money)
	{
		super(name,ID,password,money);
	}

	boolean getMoney(int m)
	{
		if(m<0)
			{
			if(saveMoney(-m))
				return true;
			else
				return false;
			}
		else
		{
			if(m-5000>money)
			{
				 System.out.println("Warning：该账户透支不可超过5000元,本次操作中断！");
				 return false;
			}
			this.money-=m;
			return true;
		}
	}

	void moveMoney(Cust st[])
	{
		System.out.println("请输入目标帐户ID:");
		int id=KB.scanInt();
		int i;
		for(i=0;i<st.length;i++)
		{
			if(st[i].ID==id)
			{
				System.out.println("请输入目标帐户密码：");
				if(st[i].checkpw())
				{
					System.out.println("请输入转账金额：");
					int m=KB.scanInt();
					if(this.getMoney(m))
					{
						st[i].saveMoney(m);
						System.out.println("转账成功!");
					}
					else
					{
						System.out.println("Warning:转账失败!");						
					}
				return ;	
				}
			}
		}
		if(i==st.length)
			System.out.println("Warning:用户不存在!");
	}

	void run(Cust st[])
	{

		while(true)
		{
			printMenu();
			int cmd=KB.scanInt();
			switch(cmd)
			{
			case 1:
			{
				System.out.println("请输入存款数：");
				int m=KB.scanInt();
				saveMoney(m);
				break;
			}
			case 2:
			{
				System.out.println("请输入取款数：");
				int m=KB.scanInt();
				getMoney(m);
				break;
			}
			case 3:
				search();break;
			case 4:
				moveMoney(st);break;
			case 0:return;
			}
		}
	}

	static void printMenu()
	{
		//System.out.println("诚信银行");
		System.out.println("——————");
		System.out.println("存款——1");
		System.out.println("取款——2");
		System.out.println("查余——3");
		System.out.println("转账——4");
		System.out.println("退出——0");
		System.out.println("——————");
	}
}
//测试类,主函数
public class Test {

	/**
	 * @WrittenBy:http://hi.baidu.com/duxing
	 */
	public static void main(String[] args) {
		Cust st[]=new Cust[4];
		st[0]=new Cust("admin",0,0,0);
		st[1]=new Cust("笃行",111,111,1000);
		st[2]=new CustVip("冬梅",222,222,2000);
		st[3]=new CustVip("乐乐",333,333,3000);
		while(true)
		{
			System.out.println("请输入帐户ID：");
			int id=KB.scanInt();
			if(id==0)return;
			int i;
			for(i=0;i<st.length;i++)
			{
				if(st[i].ID==id)
				{
					System.out.println("请输入帐户密码：");
					if(st[i].checkpw())
					{
						st[i].run(st);
						break;
					}
				}			
			}
			if(i==st.length)
			{
				System.out.println("Warning：该用户不存在！");
			}	
		}		
	}
}
//获取键盘输入类
import java.io.*;

public class KB 
{
	public static String scan()
	{
		String str = "";
		try
		{
			BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));
			str = buf.readLine();
		}
		catch (Exception e)
		{
		}
		return str;
	}
	public static int scanInt()
	{
		int temp=0;
		while(true)
		{

			try {
				temp=Integer.parseInt(scan());		
				break;
			} catch (Exception e) {
				System.out.println("Warning：输入不合法，请输入整数：");
			}			
		}
		return temp;
	}
}