多线程/售票

 1 public class Ticket {
 2         private int num = 30;
 3         Lock lock = new ReentrantLock();
 4 
 5         public void sale(){
 6             lock.lock();
 7             try{
 8                 if(num>0){
 9                     
10  System.out.println(Thread.currentThread().getName()+"\\t卖 
11   出第："+(num--)+"\\t还剩下："+num);
12                 }
13             }catch(Exception e){
14                 e.printStackTrace();
15             }finally {
16                 lock.unlock();
17             }
18         }
19     public static void main(String[] args) {
20 
21         Ticket ticket = new Ticket();
22         new Thread(()->{ for (int i = 0; i <= 40 ; i++) ticket.sale();},"A").start();
23         new Thread(()->{ for (int i = 0; i <= 40 ; i++) ticket.sale();},"B").start();
24         new Thread(()->{ for (int i = 0; i <= 40 ; i++) ticket.sale();},"C").start();
25     }