多线程售票与同步机制

先看下面的程序来售票

 1 package thread;
 2 
 3 public class Ticket {
 4     public static void main(String[] args) {
 5         SaleWindow saleWindow1 = new SaleWindow();
 6         SaleWindow saleWindow2 = new SaleWindow();
 7         SaleWindow saleWindow3 = new SaleWindow();
 8 
 9         saleWindow1.start();
10         saleWindow2.start();
11         saleWindow3.start();
12     }
13 }
14 
15 class SaleWindow extends Thread {
16     private static int ticket_num = 100;
17     @Override
18     public void run() {
19        while (true) {
20            if (ticket_num <= 0) {
21                System.out.println("售票结束");
22                break;
23            }
24            // 休眠50毫秒。模拟卖票要时间
25            try {
26                Thread.sleep(50);
27            } catch (InterruptedException e) {
28                e.printStackTrace();
29            }
30            System.out.println("当前窗口为 " + Thread.currentThread().getName() + "还剩 " + (--ticket_num) + "张票");
31 
32        }
33     }
34 }