使用java多线程实现银行取款的问题

packagecom.softeem.demo;

/**
*@author leno
*账户类
*默认有余额，可以取款
*/
class Account {
    private float balance = 1000;

    public float getBalance() {
      return balance;
    }

    public void setBalance(float balance) {
      this.balance = balance;
    }
  
    /**
    *取款的方法需要同步
    *@parammoney
    */
    public synchronized void withdrawals(float money)
    {
      if(balance>=money)
      {
          System.out.println("被取走"+money+"元!");
                   balance-=money;
      }
      else
      {
          System.out.println("对不起,余额不足!");
      }
    }
  
}

/**
*@authorleno
*银行卡
*/
class TestAccount1 extends Thread {

    private Account account;
  
  
    public TestAccount1(Account account) {
      this.account = account;
    }

    @Override
    public void run() {
      account.withdrawals(800);
      System.out.println("余额为:"+account.getBalance()+"元!");
    }
}
/**
*@authorleno
*存折
*/
class TestAccount2 extends Thread {

    private Account account;
    public TestAccount2(Account account) {
          this.account = account;
      }
    @Override
    public void run() {
      account.withdrawals(700);
      System.out.println("余额为:"+account.getBalance()+"元!");
    }
}

public class Test
{
    public static void main(String[] args) {
      Account account = new Account();
      TestAccount1 testAccount1 = new TestAccount1(account);

      TestAccount2 testAccount2 = new TestAccount2(account);
      testAccount1.start();

       try {
              Thread.sleep(1000);
          } catch (InterruptedException e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
          }

      testAccount2.start();
    }
}