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(1)业务需求：20人去买票，但是窗口只有两个，当两人中有任意一人买完后，其余十八人任意一人可以继续购买
Semaphore(信号量)：用于现在同时访问的一些数目，控制并发访问量
package com.guoanjia.common.utils;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
/**
* @author syliu
* @Title:
* @Package SemaphoreDemo
* @create 2018/5/14 0014
*/
public class SemaphoreDemo {
/**
* 控制线程任务
*/
class SemaphoreRunnable implements Runnable {
//信号量
private Semaphore semaphore;
//用户编号
private int usernum;
public SemaphoreRunnable(Semaphore semaphore, int usernum) {
this.semaphore = semaphore;
this.usernum = usernum;
}
@Override
public void run() {
try {
//获得信号量,相当于获得售票窗口
semaphore.acquire();
PrintLogger.info("用户【" + usernum + "】进入窗口买票");
Thread.sleep((long) (Math.random() * 10000));
PrintLogger.info("用户【" + usernum + "】买票完成,离开");
//释放信号量，相当于离开窗口
semaphore.release();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public void execute() {
final Semaphore semaphore = new Semaphore(2);
//获取缓存线程池
final ExecutorService executorService = Executors.newCachedThreadPool();
for (int i = 1; i < 21; i++) {
executorService.execute(new SemaphoreRunnable(semaphore, i));
}
//关闭线程任务
executorService.shutdown();
}
public static void main(String[] args) {
final SemaphoreDemo semaphoreDemo = new SemaphoreDemo();
semaphoreDemo.execute();
}
} |