一道同步机制的练习

package java1;

class Account{//账户
    private double balance;//余额

    public Account(double balance) {
        this.balance = balance;
    }

    //存钱
    //因为下面的两个顾客用的同一个acct，所以下面这个方法的锁this是唯一的。
    public synchronized void deposit(double amt){
        if(amt > 0){
            balance += amt;
            System.out.println(Thread.currentThread().getName() + ":存钱成功。余额为：" + balance);
        }
    }
}

class Customer extends  Thread{

    private Account acct;

    public Customer(Account acct) {
        this.acct = acct;//目的是两个顾客用一个账户
    }

    @Override
    public void run() {

        for (int i = 0; i < 3; i++) {
            acct.deposit(1000);
        }

    }
}


public class AccountTest {

    public static void main(String[] args) {
        Account acct = new Account(0);//一开始账户为0，没有钱
        //两个顾客用一个账户
        Customer c1 = new Customer(acct);
        Customer c2 = new Customer(acct);

        c1.setName("甲");
        c2.setName("乙");

        c1.start();
        c2.start();
    }
}