Semaphore信号量的使用

package ThreadTest;

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

public class ThreadTest04 {
    public static void main(String[] args) {
        Semaphore semaphore = new Semaphore(3);//表示3个车位
        for (int i = 0; i < 6; i++) {
            new Thread(()->{
                try {
                    semaphore.acquire();
                    System.out.println(Thread.currentThread().getName() + "获得车位");
                    TimeUnit.SECONDS.sleep(2);
                    System.out.println(Thread.currentThread().getName() + "离开车位");
                }catch (Exception e){
                    e.printStackTrace();
                }finally {
                    semaphore.release();
                }
            }, String.valueOf(i)).start();
        }
    }
}