Mybatis-Plus 真正的批量插入实现

package com.dj.springtest.config;

import com.baomidou.mybatisplus.core.injector.AbstractMethod;
import com.baomidou.mybatisplus.core.injector.DefaultSqlInjector;
import com.baomidou.mybatisplus.extension.injector.methods.InsertBatchSomeColumn;

import java.util.List;

/**
 * User: ldj
 * Date: 2023/7/13
 * Time: 23:40
 * Description: 自定义Sql注入器,只要类  ? extends AbstractMethod,就可以在BaserMapper的基础上,就可以拓展自定义的
 * 方法类,其中InsertBatchSomeColumn 是mybatis plus帮我们做好的,因为它底层是拼接sql,不同的数据库sql脚本有些许不一样,目前
 * 只在mysql测试过,所以官方没有将它暴露给我们直接使用,二是让我们自己进行扩展
 */
public class CustomSqlInjector extends DefaultSqlInjector {

    @Override
    public List getMethodList(Class mapperClass) {
        List methodList = super.getMethodList(mapperClass);
        methodList.add(new InsertBatchSomeColumn());
        return methodList;
    }
}

package com.dj.springtest.config;

import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * User: ldj
 * Date: 2023/7/13
 * Time: 23:34
 * Description: No Description
 */
@Configuration
public class MybatisPlusConfig {

    @Bean
    @ConditionalOnMissingBean(CustomSqlInjector.class)
    public CustomSqlInjector customSqlInjector() {
        return new CustomSqlInjector();
    }
}

 

package com.dj.springtest.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;

import java.util.List;

/**
 * User: ldj
 * Date: 2023/7/13
 * Time: 23:33
 * Description: 拓展Mapper,暴露方法insertBatchSomeColumn()
 */
public interface RootMapper extends BaseMapper {

    Integer insertBatchSomeColumn(List entityList);

    //解决大数据插入,insertBatchSomeColumn报错问题
    default void saveBatchByList(List list, Integer subSize) {
        List arrayList = null;
        for (int beginIndex = 0; beginIndex < list.size(); beginIndex += subSize) {
            int endIndex = Math.min(beginIndex + subSize, list.size());
            arrayList = list.subList(beginIndex, endIndex);
            insertBatchSomeColumn(arrayList);
            //arrayList.clear(); //有bug 插入数据大概会丢失1/3
        }
        assert arrayList != null;
        arrayList.clear();
    }
}

 使用:

 测试:

package com.dj.springtest;

import com.dj.springtest.mapper.UserMapper;
import com.dj.springtest.model.entity.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.ArrayList;
import java.util.List;

@SpringBootTest
class SpringTestApplicationTests {

    @Autowired
    private UserMapper userMapper;

    @Test
    void contextLoads() {
        List list = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            User user = new User();
            user.setUsername("ldj" + i);
            user.setAge(18 + i);
            user.setPassword("155255wretr");
            user.setMobile("15582060");
            list.add(user);
        }

        System.out.println(list.size());
        userMapper.saveBatchByList(list, 3);
    }

}