4、对继承自Runnable的线程进行锁机制的使用

package com.lfy.ThreadsSynchronize;import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;public class TicketSellSolution4 implements Runnable {    private static int num = 50;    //创建一个锁对象    Lock l = new ReentrantLock();        @Override    public void run() {        for(int i = 0 ; i < 50 ;i ++){            //获取锁            l.lock();            try {                if(num > 0){                    Thread.sleep(10);                    System.out.println(Thread.currentThread().getName()+"卖出一张票，剩余"+(--num)+"张");                }            } catch (Exception e) {                e.printStackTrace();            }finally{                //释放锁                l.unlock();            }        }    }}