美团面试题,千万级数据找一条数据测试

也算是对JUC这一部分的实际测试 ,确实速度很快 ,我造了1亿数据,就是CPU有点吃力

package com.xzff.web;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CountDownLatch;

/**
 * 模拟 1亿个数据中,查找一个数字
 */
public class MyTest {
    static volatile List<Integer> list = new ArrayList<>();
    static volatile int list_index = 0;
    static volatile int index = 0;
    static Object o = new Object();

    public static void addList() {
        long l = System.currentTimeMillis();
        for (int i = 0; i < 100000000L; i++) {
            list.add(i);
        }
        long l1 = System.currentTimeMillis();
        System.out.println("跑数据用时:" + (l1 - l) + "毫秒");

    }

    public static void main(String[] args) {
        CountDownLatch latch = new CountDownLatch(1);
        addList();
        long star
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