Spring Boot分段处理List集合多线程批量插入数据

项目场景：

大数据量的List集合，需要把List集合中的数据批量插入数据库中。

解决方案：

拆分list集合后，然后使用多线程批量插入数据库

1.实体类

package com.test.entity;import lombok.Data;@Data
public class TestEntity {private String id;private String name;
}

2.Mapper

如果数据量不大，用foreach标签就足够了。如果数据量很大，建议使用batch模式。

package com.test.mapper;import java.util.List;import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;import com.test.entity.TestEntity;public interface TestMapper {/*** 1.用于使用batch模式，ExecutorType.BATCH开启批处理模式* 数据量很大，推荐这种方式*/@Insert("insert into test(id, name) "+ " values"+ " (#{id,jdbcType=VARCHAR}, #{name,jdbcType=VARCHAR})")void testInsert(TestEntity testEntity);/*** 2.使用foreach标签，批量保存* 数据量少可以使用这种方式*/@Insert("insert into test(id, name) "+ " values"+ " <foreach collection='list' item='item' index='index' separator=','>"+ " (#{item.id,jdbcType=VARCHAR}, #{item.name,jdbcType=VARCHAR})"+ " </foreach>")void testBatchInsert(@Param("list") List<TestEntity> list);
}

3.spring容器注入线程池bean对象

package com.test.config;import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;@Configuration
@EnableAsync
public class ExecutorConfig {/*** 异步任务自定义线程池*/@Bean(name = "asyncServiceExecutor")public Executor asyncServiceExecutor() {ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();//配置核心线程数executor.setCorePoolSize(50);//配置最大线程数executor.setMaxPoolSize(500);//配置队列大小executor.setQueueCapacity(300);//配置线程池中的线程的名称前缀executor.setThreadNamePrefix("testExecutor-");// rejection-policy：当pool已经达到max size的时候，如何处理新任务// CALLER_RUNS：不在新线程中执行任务，而是有调用者所在的线程来执行executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());//调用shutdown()方法时等待所有的任务完成后再关闭executor.setWaitForTasksToCompleteOnShutdown(true);//等待所有任务完成后的最大等待时间executor.setAwaitTerminationSeconds(60);return executor;}
}

4.创建异步线程业务类

package com.test.service;import java.util.List;
import java.util.concurrent.CountDownLatch;import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;import com.test.entity.TestEntity;
import com.test.mapper.TestMapper;@Service
public class AsyncService {@Autowiredprivate SqlSessionFactory sqlSessionFactory;@Async("asyncServiceExecutor")public void executeAsync(List<String> logOutputResults, CountDownLatch countDownLatch) {try{//获取session，打开批处理，因为是多线程，所以每个线程都要开启一个事务SqlSession session = sqlSessionFactory.openSession(ExecutorType.BATCH);TestMapper mapper = session.getMapper(TestMapper.class);//异步线程要做的事情for (int i = 0; i < logOutputResults.size(); i++) {System.out.println(Thread.currentThread().getName() + "线程：" + logOutputResults.get(i));TestEntity test = new TestEntity();//test.set()//.............//批量保存mapper.testInsert(test);//每1000条提交一次防止内存溢出if(i%1000==0){session.flushStatements();}}//提交剩下未处理的事务session.flushStatements();}finally {countDownLatch.countDown();// 很关键, 无论上面程序是否异常必须执行countDown,否则await无法释放}}
}

5.拆分list调用异步的业务方法

package com.test.service;import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;import javax.annotation.Resource;import org.springframework.stereotype.Service;@Service
public class TestService {@Resourceprivate AsyncService asyncService;public int testMultiThread() {List<String> logOutputResults = getTestData();//按线程数拆分后的listList<List<String>> lists = splitList(logOutputResults);CountDownLatch countDownLatch = new CountDownLatch(lists.size());for (List<String> listSub:lists) {asyncService.executeAsync(listSub, countDownLatch);}try {countDownLatch.await(); //保证之前的所有的线程都执行完成，才会走下面的；// 这样就可以在下面拿到所有线程执行完的集合结果} catch (Exception e) {e.printStackTrace();}return logOutputResults.size();}public List<String> getTestData() {List<String> logOutputResults = new ArrayList<String>();for (int i = 0; i < 3000; i++) {logOutputResults.add("测试数据"+i);}return logOutputResults;}public List<List<String>> splitList(List<String> logOutputResults) {List<List<String>> results = new ArrayList<List<String>>();/*动态线程数方式*/// 每500条数据开启一条线程int threadSize = 500;// 总数据条数int dataSize = logOutputResults.size();// 线程数，动态生成int threadNum = dataSize / threadSize + 1;/*固定线程数方式// 线程数int threadNum = 6;// 总数据条数int dataSize = logOutputResults.size();// 每一条线程处理多少条数据int threadSize = dataSize / (threadNum - 1);*/// 定义标记,过滤threadNum为整数boolean special = dataSize % threadSize == 0;List<String> cutList = null;// 确定每条线程的数据for (int i = 0; i < threadNum; i++) {if (i == threadNum - 1) {if (special) {break;}cutList = logOutputResults.subList(threadSize * i, dataSize);} else {cutList = logOutputResults.subList(threadSize * i, threadSize * (i + 1));}results.add(cutList);}return results;}
}

5.Controller测试

@RestController
public class TestController {@Resourceprivate TestService testService;@RequestMapping(value = "/log", method = RequestMethod.GET)@ApiOperation(value = "测试")public String test() {testService.testMultiThread();return "success";}
}