在插入大量數(shù)據(jù)的時(shí)候,多數(shù)人會(huì)選擇批量插入來(lái)提高效率,下面文章將和大家分享一下mybatis在使用批量插入大量數(shù)據(jù)的一個(gè)具體的優(yōu)化過(guò)程。
數(shù)據(jù)庫(kù) 在使用mybatis插入大量數(shù)據(jù)的時(shí)候,為了提高效率,放棄循環(huán)插入,改為批量插入,mapper如下:
package com.lcy.service.mapper;
import com.lcy.service.pojo.TestVO;
import org.apache.ibatis.annotations.Insert;
import java.util.List;
public interface TestMapper {
@Insert("")
Integer testBatchInsert(List list);
}
實(shí)體類:
package com.lcy.service.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class TestVO {
private String t1;
private String t2;
private String t3;
private String t4;
private String t5;
}
測(cè)試類如下:
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;
@SpringBootTest(classes = TestApplication.class)
@RunWith(SpringRunner.class)
public class TestDemo {
@Autowired
private TestMapper testMapper;
@Test
public void insert() {
List 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));
}
}
為了復(fù)現(xiàn)bug,我限制了JVM內(nèi)存:
執(zhí)行測(cè)試類報(bào)錯(cuò)如下:
java.lang.OutOfMemoryError: Java heap space
at java.base/java.util.Arrays.copyOf(Arrays.java:3746)
可以看到,Arrays在申請(qǐng)內(nèi)存的時(shí)候,導(dǎo)致棧內(nèi)存溢出
改進(jìn)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;
@SpringBootTest(classes = TestApplication.class)
@RunWith(SpringRunner.class)
public class TestDemo {
@Autowired
private TestMapper testMapper;
@Test
public void insert() {
List 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流表達(dá)式,skip表示跳過(guò)前i*10000條記錄,limit表示讀取當(dāng)前流的前10000條記錄
testMapper.testBatchInsert(list.stream().skip(i*10000).limit(10000).collect(Collectors.toList()));
}
}
}
還有一種方法是調(diào)高JVM內(nèi)存,不過(guò)不建議使用,不僅吃內(nèi)存,而且數(shù)據(jù)量過(guò)大會(huì)導(dǎo)致sql過(guò)長(zhǎng)報(bào)錯(cuò)
到此這篇關(guān)于mybatis中使用批量插入大量數(shù)據(jù)的詳細(xì)內(nèi)容就介紹到這了,想要了解更多相關(guān)mybatis的內(nèi)容,請(qǐng)搜索W3Cschool以前的文章或繼續(xù)瀏覽下面的相關(guān)文章!