通过锁对象实现买票

import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;


public class SellTicket implements Runnable{


private int tickets = 100;


//定义锁对象
private Lock lock = new ReentrantLock();

@Override
public void run() {
// TODO Auto-generated method stub

while(true){

try{
//加锁
lock.lock();

if(tickets > 0){
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName() +"正在出售第" +(tickets--) + "张票");
}
}finally{
//释放锁
lock.unlock();
}
}
}

}

/*
 * 虽然我们可以理解同步代码块和同步方法的锁对象问题，但是我们并没有直接看到在哪里加上了锁，在哪里释放了锁，
 * 为了更清晰的表达如何加锁和释放锁，JDK5以后提供了一个新的锁对象Lock
 * 
 * Lock:
 *     void lock():获取锁
 *     void unlock():释放锁
 * ReentrantLock是Lock的实现类
 */
public class SellTicketDemo {


public static void main(String[] args) {
// TODO Auto-generated method stub


//创建资源对象
SellTicket st = new SellTicket();

//创建三个窗口
Thread t1 = new Thread(st,"窗口1");
Thread t2 = new Thread(st,"窗口2");
Thread t3 = new Thread(st,"窗口3");

//启动线程
t1.start();
t2.start();
t3.start();
}


}