MySemaphore.java

package test;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;

public class MySemaphore extends Thread {
    Semaphore position;
    private int id;

    public MySemaphore(int i, Semaphore s) {
        this.id = i;
        this.position = s;
    }

    public static void main(String args[]) {
        ExecutorService list = Executors.newCachedThreadPool();
        Semaphore position = new Semaphore(2);
        for (int i = 0; i < 10; i++) {
            list.submit(new MySemaphore(i + 1, position));
        }
        list.shutdown();
        position.acquireUninterruptibly(2);
        System.out.println("使用完毕，需要清扫了");
        position.release(2);
    }

    public void run() {
        try {
            if (position.availablePermits() > 0) {
                System.out.println("顾客[" + this.id + "]进入厕所，有空位");
            } else {
                System.out.println("顾客[" + this.id + "]进入厕所，没空位，排队");
            }
            position.acquire();
            System.out.println("顾客[" + this.id + "]获得坑位");
            Thread.sleep((int) (Math.random() * 10000));
            System.out.println("顾客[" + this.id + "]使用完毕");
            position.release();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}