用Java编写一个简单的存款

Question

package desposit.money;

public class DespositMoney {

    public static void main(String[] args) {
        Customer c1 = new Customer("第一个顾客",3);
        Customer c2 = new Customer("第二个顾客",10); 
        Customer c3 = new Customer("第三个顾客",5); 

        c1.start();
        c2.start();
        c3.start();
    }

}

class Customer extends Thread{
    private int time;
    String s;
    public Customer(String s,int time){
        this.s = s;
        this.time = time;
    }
    public void run(){
        while(true)
        {
            synchronized(this){
                            
                if(time>0)    
                {
                    Total.sum+=100;
                    System.out.println(s+"存款100元，银行总共有存款"+Total.sum+"元");
                    try {
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    time --;
                }
                    
                if(time ==0)
                {
                    System.out.println(s+"存款结束");
                    break;
                }
            }
        }
    }    
    
}

class Total {
    public static int sum = 0;
}

运行结果不是从100,200，......，到1800，中间总有重复的数字，但最后的结果总和是1800

Answer 1

When multiple threads access the same object, adding synchronized(this) can allow only one thread to process it at a time, but you have 3 new objects here.

Answer 2

I feel like I have to doubt your eclipse. I copied the code completely and re-ran it. The result is this:
There are no repeated numbers. I deposit money in order and the result is also correct