如何实现用Java写一个模拟ATM机程序

/** 
     * 账户类; 
     * @author Administrator 
     * 
     */  
    public class Account {  

        private String name;  //用户名;  
        private int value;    //账户余额;  

        /** 
         * 存入金额; 
         * @param monery 
         */  
        public void putMonery(int monery){  
            this.value = this.value + monery;   
        }  

        /** 
         * 取出金额; 
         * @param monery 
         * @return 金额; 
         */  
        public int getMonery(int monery){  

            //判断是否账户余额是否大于 要取出的钱;  
            if(this.value > monery ){  
                this.value = this.value - monery;     
            }else{  
                monery = this.value;  //账户余额不够时,则取出,所有的账户余额的金额.   
                this.value = 0;  
            }  
            //返回取出的钱;  
            return monery;  
        }  

        /** 
         * 查询余额; 
         * @return 返回账户余额; 
         */  
        public int search(){  
            return this.value;  
        }  

        public String getName() {  
            return name;  
        }  
        public void setName(String name) {  
            this.name = name;  
        }  
        public int getValue() {  
            return value;  
        }  
        public void setValue(int value) {  
            this.value = value;  
        }  
    }

/** 
 * 取款线程类; 
 * @author Administrator 
 * 
 */  
public class FetchMoney extends Thread implements Serializable{  

    private static final long serialVersionUID = -5059599151558445815L;  

    private Account account;  //账户对象;  
    private int monery;       //余额;  

    public FetchMoney(){  
        super();  
    }  

    public FetchMoney(int monery,Account account){  
        this.account = account;  
        this.monery = monery;  
    }  

    @Override  
    public void run() {  
        // TODO Auto-generated method stub  
        int currMonery  = account.search();  //当前余额;  
        synchronized (account) {  
            try {  
                sleep(5);   //取款发费的时间;  
            } catch (InterruptedException e) {  
                // TODO Auto-generated catch block  
                e.printStackTrace();  
            }  
            //取出余额;  
            int getMonery = account.getMonery(monery);  
            System.out.println("尊敬的"+account.getName()+"用户您好!"+"当前的余额为:"+currMonery +"元."+"取出余额为:"+getMonery+"元."+"账户余额为:"+account.search()+"元");  
        }  
    }  
}

/** 
 * 存款线程类; 
 * @author Administrator 
 * 
 */  
public class SaveMoney extends Thread implements Serializable{  

    private static final long serialVersionUID = 3095120546560212724L;  

    private Account account;  //账户对象;  
    private int money;        //金额;  

    public SaveMoney(){  
        super();  
    }  

    public SaveMoney(int money,Account account){  
        this.account = account;  
        this.money = money;  
    }  

    @Override  
    public void run() {  
        // TODO Auto-generated method stub  
        int currMonery = account.search(); //查询账户余额;  

        //同步对象,只允许单线程操作;  
        synchronized (account) {  
            try {  
                sleep(5);  //查询的时候,发费得时间;  
            } catch (InterruptedException e) {  
                // TODO Auto-generated catch block  
                e.printStackTrace();  
            }  
            account.putMonery(this.money);   //插入金额;  
            //输出存款信息;  
            System.out.println("尊敬的"+account.getName()+"用户您好!"+"当前的余额为:"+currMonery +"元."+"存入余额为:"+this.money+"元."+"账户余额为:"+account.search()+"元");  
        }  
    }  
}

/** 
 * ATM测试类; 
 * @author Administrator 
 * 
 */  
public class ThreadATMDemo {  

    /** 
     * 主方法; 
     * @param args 
     */  
    public static void main(String[] args) {  
        // TODO Auto-generated method stub  
        Account account = new Account();  
        //设置用户名;  
        account.setName("ZhouHaiTao");  
        //初始化余额;  
        account.setValue(0);  

        //存入100;  
        new SaveMoney(100,account).start();  

        //存入200;  
        new SaveMoney(200, account).start();  

        //取出500;  
        new FetchMoney(500, account).start();  
    }  
}