JAVA多線程CountDownLatch倒計時鎖應用

package concurrent;

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

/**
 * Auth: zhouhongliang
 * Date：2019/8/1
 * CountDownLatch倒計時鎖
 * 阻塞主線程，等子線程全部執行完之后主線程繼續執行
 *
 */
public class CountDownLatchDemo {
    public static int count = 0;
    /**
     * 計算1至10000的和
     * @param args
     */
    public static void main(String[] args) throws InterruptedException {
        //定義一個緩沖線程池
        ExecutorService executorService = Executors.newCachedThreadPool();
        //定義一個倒計時鎖
        CountDownLatch countDownLatch = new CountDownLatch(10000);
        for (int i=1;i<=10000;i++){
            final int index = i;
            //多個線程執行
            executorService.execute(()->{
                synchronized (CountDownLatchDemo.class){
                    try {
                        count += index;
                    } catch (Exception e) {
                        e.printStackTrace();
                    } finally {
                        //計數器減1
                        countDownLatch.countDown();
                    }
                }
            });
        }
        //線程阻塞，知道countDownLatch計數值=0
        countDownLatch.await();
        System.out.println(count);
                //關閉線程池
        executorService.shutdown();
    }
}

輸出結果：50005000