ConcurrentlyExecuteDbQuery

验证并发数据库查询 vs 顺序数据库查询

package com.tn.api.service;

import com.tn.api.dao.TestDao;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

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

import static org.junit.Assert.assertTrue;

/**
 * Created by zhuguowei on 4/4/17.
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath:spring/spring-api.xml","classpath:spring/spring-dao.xml"})
@Slf4j
public class ConcurrentlyDbQureyTest {
    @Autowired
    private TestDao dao;

    @Test
    public void test_sleep1(){
        long start = System.currentTimeMillis();
        dao.sleep1();
        long end = System.currentTimeMillis();
        log.info("took time: {}", end - start);
        assertTrue((end - start) > 1000L);
    }
    @Test
    public void test_concurrently_invoke_sleep1() throws InterruptedException {
        long start = System.currentTimeMillis();
        int nThreads = 10;
        ExecutorService executorService = Executors.newFixedThreadPool(nThreads);
        CountDownLatch countDownLatch = new CountDownLatch(nThreads);
        for (int i = 0; i < nThreads; i++) {
            executorService.submit(()->{
                dao.sleep1();
                countDownLatch.countDown();
            });
        }
        countDownLatch.await();
        long end = System.currentTimeMillis();
        log.info("took time: {}", end - start);
        assertTrue((end - start) < 2000L);
    }
}

    @Select("select sleep(1)")
    long sleep1();