CountDownLatch的使用

最新推荐文章于 2025-11-06 21:12:11 发布

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本文通过一个医院场景的模拟，展示了Java并发工具类CountDownLatch的具体应用。通过创建医生和患者两个角色，利用CountDownLatch来同步线程，确保所有患者在医生就绪后才能开始体检流程，最后医生完成所有患者的检查后下班。此例详细解释了CountDownLatch的await()和countDown()方法的使用。

package com.example.sina.thread;

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

public class CountDownLatchTest {

public static void main(String[] args) {

       // 医生
       CountDownLatch hospitalLatch = new CountDownLatch(1);
       // 患者
       CountDownLatch patientLatch = new CountDownLatch(10);

System.out.println("患者排队");

       System.out.println("医生上班");

       // 创建一个可缓存的线程池
       ExecutorService executorService = Executors.newCachedThreadPool();

       for (int i = 0; i < 10; i++) {
           final int j = i;
           executorService.execute(() -> {
               try {
                   hospitalLatch.await();
               } catch (InterruptedException e) {
                   e.printStackTrace();
               }
               System.out.println("体检：" + j);
               patientLatch.countDown();
           });
       }
       hospitalLatch.countDown();
       try {
           patientLatch.await();
       } catch (InterruptedException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
       System.out.println("医生下班");
       executorService.shutdown();
   }
}