weixin_43688217的博客

package com.pa.test.JUC.support; import java.util.concurrent.CountDownLatch; /** * CountDownLatch 减法计数器 * 原理: * countDownLatch.countDown(); //数量-1 * countDownLatch.await(); //执行等待 等待计数器归零,然后在向下执行 * 每次有线程调用countDownLatch.countDown()数量-1 ,当计数器为0 , co.