mybatis批量插入10万条数据的优化过程

在使用mybatis插入大量数据的时候,为了提高效率,放弃循环插入,改为批量插入,mapper如下:

package com.lcy.service.mapper;import com.lcy.service.pojo.TestVO;
import org.apache.ibatis.annotations.Insert;import java.util.List;/*** 功能描述：** @author liuchaoyong* @version 1.0* @date 2019-06-26 13:18*/
public interface TestMapper {@Insert("<script>" +"insert into test (t1,t2,t3,t4,t5) values " +"<foreach collection='list' item='obj' separator=','>" +"(#{obj.t1},#{obj.t2},#{obj.t3},#{obj.t4},#{obj.t5})" +"</foreach>" +"</script>")Integer testBatchInsert(List<TestVO> list);}

实体类:

package com.lcy.service.pojo;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;/*** 功能描述：** @author liuchaoyong* @version 1.0* @date 2019-06-26 13:20*/
@Data
@NoArgsConstructor
@AllArgsConstructor
public class TestVO {private String t1;private String t2;private String t3;private String t4;private String t5;}

测试类如下:

import com.lcy.service.TestApplication;
import com.lcy.service.mapper.TestMapper;
import com.lcy.service.pojo.TestVO;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;import java.util.ArrayList;
import java.util.List;/*** 功能描述：** @author liuchaoyong* @version 1.0* @date 2019-05-17 16:42*/
@SpringBootTest(classes = TestApplication.class)
@RunWith(SpringRunner.class)
public class TestDemo {@Autowiredprivate TestMapper testMapper;@Testpublic void insert() {List<TestVO> list = new ArrayList<>();for (int i = 0; i < 200000; i++) {list.add(new TestVO(i + "," + i, i + "," + i, i + "," + i, i + "," + i, i + "," + i));}System.out.println(testMapper.testBatchInsert(list));}}

为了复现bug,我限制了JVM内存:

在这里插入图片描述
执行测试类报错如下:

java.lang.OutOfMemoryError: Java heap spaceat java.base/java.util.Arrays.copyOf(Arrays.java:3746)

可以看到,Arrays在申请内存的时候,导致栈内存溢出

改进方法,分批新增:

import com.lcy.service.TestApplication;
import com.lcy.service.mapper.TestMapper;
import com.lcy.service.pojo.TestVO;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;import javax.swing.*;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;/*** 功能描述：** @author liuchaoyong* @version 1.0* @date 2019-05-17 16:42*/
@SpringBootTest(classes = TestApplication.class)
@RunWith(SpringRunner.class)
public class TestDemo {@Autowiredprivate TestMapper testMapper;@Testpublic void insert() {List<TestVO> list = new ArrayList<>();for (int i = 0; i < 200000; i++) {list.add(new TestVO(i + "," + i, i + "," + i, i + "," + i, i + "," + i, i + "," + i));}int index = list.size() / 10000;for (int i=0;i< index;i++){//stream流表达式，skip表示跳过前i*10000条记录，limit表示读取当前流的前10000条记录testMapper.testBatchInsert(list.stream().skip(i*10000).limit(10000).collect(Collectors.toList()));}}}