java的Lock锁解决线程安全 -----> JDK5.0新增

import java.util.concurrent.locks.ReentrantLock;
// 测试
public class LockTest {
    public static void main(String[] args) {
        Windows w = new Windows();
         
        Thread t1 = new Thread(w);
        Thread t2 = new Thread(w);
        Thread t3 = new Thread(w);
         
        t1.setName("窗口一");
        t2.setName("窗口二");
        t3.setName("窗口三");
         
        t1.start();
        t2.start();
        t3.start();
    }
}
 
class Windows implements Runnable{
     
    private int ticket = 100;
    // 1.实例化ReentrantLock
    private ReentrantLock lock = new ReentrantLock();
     
    @Override
    public void run() {
        while (true) {
            try {
                // 2.调用锁定方法:lock()
                lock.lock();
                if (ticket > 0) {
                    try {
                        Thread.sleep(100);                 
                    }catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(Thread.currentThread().getName() + ":买票,票号为:" + ticket);
                    ticket--;
                }else {
                    break;
                }
            }finally {
                // 3.调用解锁方法: unlock()
                lock.unlock();
            }
        }
    }
}