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mybatis批量插入大量數(shù)據(jù)該如何優(yōu)化呢？詳細優(yōu)化過程講解

深淵的那支花 2021-08-10 11:14:35 瀏覽數(shù) (4143)
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在插入大量數(shù)據(jù)的時候，多數(shù)人會選擇批量插入來提高效率，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)的一個具體的優(yōu)化過程。

數(shù)據(jù)庫 在使用mybatis插入大量數(shù)據(jù)的時候,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));
    }

}

為了復現(xiàn)bug,我限制了JVM內(nèi)存:

202141690026090

執(zhí)行測試類報錯如下:

java.lang.OutOfMemoryError: Java heap space

 at java.base/java.util.Arrays.copyOf(Arrays.java:3746)

可以看到,Arrays在申請內(nèi)存的時候,導致棧內(nèi)存溢出

改進方法,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流表達式，skip表示跳過前i*10000條記錄，limit表示讀取當前流的前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,不過不建議使用,不僅吃內(nèi)存,而且數(shù)據(jù)量過大會導致sql過長報錯

到此這篇關于mybatis中使用批量插入大量數(shù)據(jù)的詳細內(nèi)容就介紹到這了，想要了解更多相關mybatis的內(nèi)容，請搜索W3Cschool以前的文章或繼續(xù)瀏覽下面的相關文章！

Java

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