java实现银行转账

{
    public static void main(String[] args) {
        //创建一个客户对象
        Scanner input = new Scanner(System.in);
        Customer c1 = new Customer();
        c1.name ="客户1";
        c1.tel = "10086";
        c1.cid = "1010";
        //创建一个账户
        Account a1 = new Account();
        a1.id = "001";
        a1.balance = 200.0;
        //创建一个银行对象
        BankClerk b1 = new BankClerk();
        b1.open(c1,a1);//客户和账户进行绑定 c1.acc = a1
        System.out.println("客户名："+c1.name+ "，电话：" + c1.tel +
                "，身份证号：" + c1.cid + "，账号id是:"+c1.acc.id+
                "，余额：" + c1.acc.balance);
        //第二个客户
        Customer c2 = new Customer();
        c2.name ="客户2";
        c2.tel = "10010";
        c2.cid = "0101";
        //创建一个账户
        Account a2 = new Account();
        a2.id = "002";
        a2.balance = 100.0;
        //创建一个银行对象
        BankClerk b2 = new BankClerk();
        b2.open(c2,a2);//客户和账户进行绑定 c1.acc = a1
        System.out.println("客户名："+c2.name+ "，电话：" + c2.tel +
                "，身份证号：" + c2.cid + "，账号id是:"+c2.acc.id+
                "，余额：" + c2.acc.balance);
        c1.acc.withdraw(500); //取钱
        System.out.println("客户名："+c1.name+"余额："+ c1.acc.balance);
        c1.acc.save(500); //存钱
        System.out.println("客户名："+c1.name+"余额："+ c1.acc.balance);
        System.out.println("请输入转账金额：");
        double a = input.nextDouble();
        System.out.println("客户1转账给客户2请选择 1");
        System.out.println("客户2转账给客户1请选择 2");
        int b = input.nextInt();
        switch (b){
            case 1:
                if (a<= a1.balance) {
                    c1.acc.transfer(a);
                    c2.acc.accept(a);
                }else{
                    System.out.println("余额不足");
                }break;
            case 2:
                if (a<=a2.balance){
                c2.acc.transfer(a);
                c1.acc.accept(a);
                }else {
                    System.out.println("余额不足");
                }break;
        }
        //最后打印客户相关信息
        System.out.println("客户名："+c1.name+ "，电话：" + c1.tel +
                "，身份证号：" + c1.cid + "，账号id是:"+c1.acc.id+
                "，余额：" + c1.acc.balance);
        System.out.println("客户名："+c2.name+ "，电话：" + c2.tel +
                "，身份证号：" + c2.cid + "，账号id是:"+c2.acc.id+
                "，余额：" + c2.acc.balance);
    }
}