此篇文章与前面：多线程:Future批量插入数据到mysql(一) 对应的解决同一个问题得两种方法。
即：多线程，向数据库批量插入数据
步骤：第一步，在控制层构造一百万数据（实际开发可能是接收其他地方的数据）

package com.sinux.cc.batchoperate.controller;import com.sinux.cc.batchoperate.entity.SysUser;
import com.sinux.cc.batchoperate.service.ISysUserService;
import com.sinux.cc.utils.R;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Random;
/*** @author * @since 2020-06-26*/
@RestController
@RequestMapping("/batchoperate/sys-user")
@Api(tags = "批量操作")
public class SysUserController {@Autowiredprivate ISysUserService iSysUserService;@PostMapping("/batchInsertbyrun")@ApiOperation(value = "Run方法多线程：批量插入数据")public R batchInsertByRun() {List<SysUser> list = new ArrayList<>();for (int i = 0; i < 1000000; i++) {SysUser su = new SysUser();su.setUsername("美美" + i);su.setPassword("i love you " + i);su.setRoleId(i);su.setLoginTime(new Date());list.add(su);}boolean a = iSysUserService.batchInsertByRun(list);if (a) {return R.ok();} else {return R.error();}}
}

接口：interface

boolean batchInsertByRun(List<SysUser> list);

②在实现类中调用 runnable（记住：runnable方法的使用）

@Overridepublic boolean batchInsertByRun(List<SysUser> list){try {new Thread(new BatchRunnable(list,sysUserMapper)).start();} catch (Exception e) {e.printStackTrace();return false;}return true;}

③写好BatchRunnable类处理批量数据（***重点***这个类没有纳入容器管理，所以这里的list和sysUserMapper都是通过构造传过来的，记住这种思维方式）

package com.sinux.cc.batchoperate.util;import com.sinux.cc.batchoperate.entity.SysUser;
import com.sinux.cc.batchoperate.mapper.SysUserMapper;import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.*;public class BatchRunnable implements Runnable{/*** 100条为分界批量导入*/private int batch500 = 500;/**mysql数据*/private List<SysUser> list;private SysUserMapper sysUserMapper;ExecutorService executorService = new ThreadPoolExecutor(4,Runtime.getRuntime().availableProcessors(),2L,TimeUnit.SECONDS,new LinkedBlockingDeque<>(12),Executors.defaultThreadFactory(),new ThreadPoolExecutor.CallerRunsPolicy());public BatchRunnable(List<SysUser> list,SysUserMapper sysUserMapper){System.out.println("当前线程："+Thread.currentThread().getName());this.list=list;this.sysUserMapper=sysUserMapper;}@Overridepublic void run() {try {batchOp(list);} catch (Exception e) {e.printStackTrace();}}private void batchOp(List<SysUser> list) {System.out.println("进入batchOp===集合长度为："+list.size());if(!list.isEmpty()){Long t1 = System.currentTimeMillis();Integer size = list.size();if(size<=batch500){sysUserMapper.insertBatch(list);}else {batchSpilitList(list);}Long t2 = System.currentTimeMillis();System.out.println("插入完毕，用时："+(t2-t1)+"毫秒");}}private void batchSpilitList(List<SysUser> list) {Long t1 = System.currentTimeMillis();List<List<SysUser>> lists = new ArrayList<>();int i=1;try {lists = BathUtil.pagingList(list,batch500);for(List<SysUser> li : lists){System.out.println("第"+i+"批数据正在插入");i++;executorService.execute(()->{System.out.println("当前线程是："+Thread.currentThread().getName());batchOp(li);});}} catch (Exception e) {e.printStackTrace();}finally {executorService.shutdown();Long t2 = System.currentTimeMillis();System.out.println("执行完成,用时…………"+(t2-t1));}}
}

④ list集合的分割方法（记住：通用方法）

public class BathUtil {public static <T> List<List<T>> pagingList(List<T> list, int pageSize) {int length = list.size();System.out.println(pageSize);int num = (length + pageSize - 1)/ pageSize;List<List<T>> newlist = new ArrayList<>();for (int i = 0; i < num; i++) {int fromIndex = i * pageSize;int toIndex = (i + 1) * pageSize < length ? (i + 1) * pageSize : length;newlist.add(list.subList(fromIndex, toIndex));}return newlist;}
}

⑤剩下的就是mapper和xml

void insertBatch(@Param("list") List<SysUser> list);

  <insert id="insertBatch">insert into sys_user(username,password,role_id,login_time)values<foreach collection="list" item="item" separator=",">(#{item.username},#{item.password},#{item.roleId},#{item.loginTime})</foreach></insert>

这里的实体类很简单：

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
public class SysUser implements Serializable {private static final long serialVersionUID = 1L;@TableIdprivate int id;private String username;private String password;private Integer roleId;private Date loginTime;
}

总结：1.在service层使用runnable的方法。在Future批量插入数据到mysql(一)中讲的是使用future实行多线程，对比总结归纳。
2.BatchRunnable 类的run方法开始使用了线程池处理批量数据插入，小批量插入数据的思维值得注意
3.集合分割BathUtil ，纯粹的技术方法。记住就好，可能会再遇到，这里是个通用的方法
4.xml里面的批量插入数据方法 foreach的使用（用的时候记得去哪里找就行）

  <insert id="insertBatch">insert into sys_user( login_time )values<foreach collection="list" item="item" separator=",">( #{item.loginTime})</foreach></insert>