使用mybatis-plus来进行批量新增和更新时，你会发现其实是一条条sql执行,下面进行优化。

1.添加InsertBatchMethod和UpdateBatchMethod类

import com.baomidou.mybatisplus.core.injector.AbstractMethod;
import com.baomidou.mybatisplus.core.metadata.TableInfo;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.executor.keygen.NoKeyGenerator;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlSource;

/**
 * 批量插入方法实现
 */
@Slf4j
public class InsertBatchMethod extends AbstractMethod {
    @Override
    public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
        final String sql = "<script>insert into %s %s values %s</script>";
        final String fieldSql = prepareFieldSql(tableInfo);
        final String valueSql = prepareValuesSql(tableInfo);
        final String sqlResult = String.format(sql, tableInfo.getTableName(), fieldSql, valueSql);
        //log.debug("sqlResult----->{}", sqlResult);
        SqlSource sqlSource = languageDriver.createSqlSource(configuration, sqlResult, modelClass);
        return this.addInsertMappedStatement(mapperClass, modelClass, "insertBatch", sqlSource, new NoKeyGenerator(), null, null);
    }

    private String prepareFieldSql(TableInfo tableInfo) {
        StringBuilder fieldSql = new StringBuilder();
        fieldSql.append(tableInfo.getKeyColumn()).append(",");
        tableInfo.getFieldList().forEach(x -> fieldSql.append(x.getColumn()).append(","));
        fieldSql.delete(fieldSql.length() - 1, fieldSql.length());
        fieldSql.insert(0, "(");
        fieldSql.append(")");
        return fieldSql.toString();
    }

    private String prepareValuesSql(TableInfo tableInfo) {
        final StringBuilder valueSql = new StringBuilder();
        valueSql.append("<foreach collection=\"list\" item=\"item\" index=\"index\" open=\"(\" separator=\"),(\" close=\")\">");
        valueSql.append("#{item.").append(tableInfo.getKeyProperty()).append("},");
        tableInfo.getFieldList().forEach(x -> valueSql.append("#{item.").append(x.getProperty()).append("},"));
        valueSql.delete(valueSql.length() - 1, valueSql.length());
        valueSql.append("</foreach>");
        return valueSql.toString();
    }
}

import com.baomidou.mybatisplus.core.injector.AbstractMethod;
import com.baomidou.mybatisplus.core.metadata.TableInfo;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlSource;

/**
 * 批量更新方法实现，条件为主键，选择性更新
 */
@Slf4j
public class UpdateBatchMethod extends AbstractMethod {
    @Override
    public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
        String sql = "<script>\n<foreach collection=\"list\" item=\"item\" separator=\";\">\nupdate %s %s where %s=#{%s} %s\n</foreach>\n</script>";
        String additional = tableInfo.isWithVersion() ? tableInfo.getVersionFieldInfo().getVersionOli("item", "item.") : "" + tableInfo.getLogicDeleteSql(true, true);
        String setSql = sqlSet(tableInfo.isWithLogicDelete(), false, tableInfo, false, "item", "item.");
        String sqlResult = String.format(sql, tableInfo.getTableName(), setSql, tableInfo.getKeyColumn(), "item." + tableInfo.getKeyProperty(), additional);
        //log.debug("sqlResult----->{}", sqlResult);
        SqlSource sqlSource = languageDriver.createSqlSource(configuration, sqlResult, modelClass);
        // 第三个参数必须和RootMapper的自定义方法名一致
        return this.addUpdateMappedStatement(mapperClass, modelClass, "updateBatch", sqlSource);
    }

}

2.添加自定义方法SQL注入器

import com.baomidou.mybatisplus.core.injector.AbstractMethod;
import com.baomidou.mybatisplus.core.injector.DefaultSqlInjector;

import java.util.List;

public class CustomizedSqlInjector extends DefaultSqlInjector {
    /**
     * 如果只需增加方法，保留mybatis plus自带方法，
     * 可以先获取super.getMethodList()，再添加add
     */
    @Override
    public List<AbstractMethod> getMethodList(Class<?> mapperClass) {
        List<AbstractMethod> methodList = super.getMethodList(mapperClass);
        methodList.add(new InsertBatchMethod());
        methodList.add(new UpdateBatchMethod());
        return methodList;
    }
}

3.注入配置

@MapperScan("com.xxx.mapper")
@Configuration
public class MyBatisPlusConfig {
    @Bean
    public CustomizedSqlInjector customizedSqlInjector() {
        return new CustomizedSqlInjector();
    }
}

4.添加通用mapper

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Param;

import java.util.List;

/**
 * 根Mapper，给表Mapper继承用的，可以自定义通用方法
 * {@link com.baomidou.mybatisplus.core.mapper.BaseMapper}
 * {@link com.baomidou.mybatisplus.extension.service.IService}
 * {@link com.baomidou.mybatisplus.extension.service.impl.ServiceImpl}
 */
public interface RootMapper<T> extends BaseMapper<T> {

    /**
     * 自定义批量插入
     * 如果要自动填充，@Param(xx) xx参数名必须是 list/collection/array 3个的其中之一
     */
    int insertBatch(@Param("list") List<T> list);

    /**
     * 自定义批量更新，条件为主键
     * 如果要自动填充，@Param(xx) xx参数名必须是 list/collection/array 3个的其中之一
     */
    int updateBatch(@Param("list") List<T> list);
}

5.如何使用

@Repository
public interface UserInfoMapper extends RootMapper<UserInfo> {
}



public interface UserInfoService extends IService<UserInfo> {

    int saveAll();

    int updateAll();
}



@Service
public class UserInfoServiceImpl extends ServiceImpl<UserInfoMapper, UserInfo> implements UserInfoService{

    @Override
    public int saveAll() {
        List<UserInfo> list = new ArrayList<>();
        for (int i = 0; i < 20; i++) {
            UserInfo userInfo = new UserInfo();
            userInfo.setUserName("厉害" + i);
            userInfo.setSalt(RandomStringUtils.randomAlphabetic(6));
            userInfo.setPassword(SecureUtil.sha256("123456" + userInfo.getSalt()));
            userInfo.setSex(0);
            userInfo.setAvatar(LoginServiceImpl.AVATAR);
            list.add(userInfo);
        }
        return baseMapper.insertBatch(list);
    }

    @Override
    public int updateAll() {
        List<UserInfo> userInfos = baseMapper.selectList(Wrappers.<UserInfo>lambdaQuery().between(BaseEntity::getId, 43, 62));
        userInfos.forEach(userInfo -> {
            userInfo.setUserName("更新了" + IdUtil.simpleUUID());
        });
        return baseMapper.updateBatch(userInfos);
    }
}