JUC之辅助类Semaphore

模拟一个样例，6辆汽车抢占3个停车位

import java.util.Random;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

//6个线程抢占3个停车位
public class SemaphoreDemo {
    public static void main(String[] args) {
        //创建Semaphore,定义许可数量
        Semaphore semaphore =new Semaphore(3);
        //定义6辆汽车
        for(int i=1;i<=6;i++){
            new Thread(()->{
                try {
                    //抢占
                    semaphore.acquire();

                    System.out.println(Thread.currentThread().getName()+"抢到了车位");

                    //设置停车时间0~1500ms
                    TimeUnit.MILLISECONDS.sleep(new Random().nextInt(1500));
                    
                    System.out.println(Thread.currentThread().getName()+"----离开了车位");

                } catch (InterruptedException e) {
                    e.printStackTrace();
                }finally {
                    semaphore.release();
                }
            },String.valueOf(i)).start();
        }
    }
}