请求合并实战版本

package com.example.demo.concurrent.requestmerge;

import com.example.demo.schedule.entity.ISysJobRepository;
import com.example.demo.schedule.entity.SysJobPO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import javax.annotation.PostConstruct;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.concurrent.*;


/**
 * 请求合并：
 * 高并发调用这里的服务,针对查询对请求进行合并,
 */
@Service(value="JobServiceImpl2")
public class JobServiceImpl2 implements IJobService {
    class Request{
        Integer jobId;
        CompletableFuture<SysJobPO> result;
    }
    //存放并发线程调用的参数
    private LinkedBlockingQueue<Request> requestQue=new LinkedBlockingQueue<>();
    @Autowired
    private ISysJobRepository jobRepository;

    /**
     * 被@PostConstruct修饰的方法会在服务器加载Servlet的时候运行，并且只会被服务器执行一次
     * 执行顺序在@Autowired之后
     */
    @PostConstruct
    public void init() {
        System.out.println("合并请求");
        ScheduledExecutorService threadPool = Executors.newScheduledThreadPool(1);
        //参数1运行的任务,参数2执行时间0立即执行,参数3间隔时间,参数4时间单位
        //每10毫秒批量查询一次队列
        threadPool.scheduleAtFixedRate(() -> {
            ArrayList<Request> requestList = new ArrayList<Request>();
            List<Integer> jobIdList = new ArrayList<Integer>();
            int size = requestQue.size();
            if(size==0)
                return;
            System.out.println("批量查询大小"+size);

            for (int i = 0; i <size; i++) {
                Request request = requestQue.poll();
                requestList.add(request);
                jobIdList.add(request.jobId);
            }
            //批量查询出所有结果
            List<SysJobPO> jobList = getSysJobListByJobIdList(jobIdList);
            //讲结果转化为map<k,v>  key为jobId value为查询的结果
            HashMap<Integer,SysJobPO> map = new HashMap<>();
            for (SysJobPO job : jobList) {
                map.put(job.getJobId(), job);
            }
            //讲结果分发给每个线程,即分发给CompletableFuture,根据jobid分发
            for (Request request : requestList) {
                request.result.complete(map.get(request.jobId));
            }
        }, 0, 10, TimeUnit.MILLISECONDS);
    }

    @Override
    public SysJobPO selectByPrimaryKey(Integer jobId) {
        Request request=new Request();
        CompletableFuture<SysJobPO> futureResult = new CompletableFuture<>();
        request.jobId=jobId;
        request.result=futureResult;
        requestQue.add(request);
        SysJobPO job=null;
        try {
            //阻塞至futureResult.complete()方法
            job = futureResult.get();
        } catch (InterruptedException | ExecutionException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return job;
    }

    @Override
    public List<SysJobPO> getSysJobListByJobIdList(List<Integer> jobIds) {
        return jobRepository.findByJobIdIn(jobIds);
    }
}

package com.example.demo.concurrent.requestmerge;

import com.example.demo.schedule.entity.SysJobPO;

import java.util.List;

public interface IJobService {
    SysJobPO selectByPrimaryKey(Integer jobId);

    List<SysJobPO> getSysJobListByJobIdList(List<Integer> jobIds);
}

package com.example.demo.concurrent;

import com.example.demo.DemoApplication;
import com.example.demo.concurrent.requestmerge.IJobService;
import com.example.demo.schedule.entity.SysJobPO;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.context.web.WebAppConfiguration;
import javax.annotation.Resource;
import java.io.IOException;
import java.util.concurrent.CountDownLatch;

//请求合并测试
@SpringBootTest(classes= DemoApplication.class)
@WebAppConfiguration
@RunWith(SpringRunner.class)
public class SpringConcurrentTest {
    @Resource(name="JobServiceImpl2")
    private IJobService jobService;
    @Test
    public void test1(){
        SysJobPO job = jobService.selectByPrimaryKey(2);
        System.out.println(job);
    }

    @Test
    public void bingfa() throws InterruptedException, IOException {
        CountDownLatch countDownLatch=new CountDownLatch(1000);
        for (int i = 0; i <1000; i++) {
            final int j=i;
            new java.lang.Thread(() -> {
                try {
                    countDownLatch.await();
                    SysJobPO job = jobService.selectByPrimaryKey(j);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            ).start();
            countDownLatch.countDown();
        }
        System.in.read();
    }
}