线程安全 List 效率测试

article/2025/8/24 12:49:34

List 常见类以及各自优缺点可自行参考 https://blog.csdn.net/weixin_39883065/article/details/111197724

本机环境

java 版本：1.8.0_161
window 信息：
请添加图片描述

测试代码

下面通过代码测试 List 线程安全类 Vector、Collections.synchronizedList(List list)、CopyOnWriteArrayList

测试添加 1 亿数据，开启 100 个线程，每个线程插入 100万

public class TestList {public static void main(String[] args) throws InterruptedException {long startTime = System.currentTimeMillis();// 线程不安全// List<Integer> list = new ArrayList<>();// 线程安全 100000000 耗时 27357// List<Integer> list = new Vector<>();// 线程安全 100000000 耗时 22023List<Integer> list = Collections.synchronizedList(new ArrayList<>());// 线程安全 100000000 耗时//List<Integer> list =new CopyOnWriteArrayList<>();int threadNum = 100;CountDownLatch countDownLatch = new CountDownLatch(threadNum);for (int i = 0; i < threadNum; i++) {Thread thread = new Thread(() -> {for (int j = 0; j < 1000000; j++) {list.add(j);}countDownLatch.countDown();});thread.start();}countDownLatch.await();long endTime = System.currentTimeMillis();System.out.println(list.size());System.out.println(list.getClass()+"耗时：          "+(endTime-startTime));}
}