springBoot+mybatisPlus+hutool 实现输入sql导出 excel表格

支持pom包

<dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.1.1</version>
        </dependency>
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>4.5.10</version>
        </dependency>
<dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.17</version>
        </dependency>

rest代码

    @GetMapping(value = "download")
    public void download(String sqlString, HttpServletResponse response) throws IOException {
        List<HashMap<String,String>> hashMaps = checkOrderService.invokeSql(sqlString);
//        Map<String, Object> row1 = new LinkedHashMap<>();
//        row1.put("姓名", "张三");
//        row1.put("年龄", 23);
//        row1.put("成绩", 88.32);
//        row1.put("是否合格", true);
//        row1.put("考试日期", DateUtil.date());
//
//        Map<String, Object> row2 = new LinkedHashMap<>();
//        row2.put("姓名", "李四");
//        row2.put("年龄", 33);
//        row2.put("成绩", 59.50);
//        row2.put("是否合格", false);
//        row2.put("考试日期", DateUtil.date());

        ArrayList<Map<String, Object>> rows = (ArrayList) hashMaps;



        // 通过工具类创建writer，默认创建xls格式
        ExcelWriter writer = ExcelUtil.getWriter();
        // 一次性写出内容，使用默认样式，强制输出标题
        writer.write(rows, true);
        //out为OutputStream，需要写出到的目标流

        //response为HttpServletResponse对象
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
            //test.xls是弹出下载对话框的文件名，不能为中文，中文请自行编码
        response.setHeader("Content-Disposition","attachment;filename=test.xls");
        ServletOutputStream out=response.getOutputStream();

        writer.flush(out, true);
        // 关闭writer，释放内存
        writer.close();
        //此处记得关闭输出Servlet流
        IoUtil.close(out);

//        checkOrderBlh.backup2(response);
    }

service

package com.mybatis.plus.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.mybatis.plus.entity.order.CheckOrder;

import java.util.HashMap;
import java.util.List;

public interface CheckOrderService extends IService<CheckOrder> {

    List<HashMap<String,String>> invokeSql(String sqlString);
}

serviceImpl

package com.mybatis.plus.service.impl;

import com.baomidou.mybatisplus.extension.service.IService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.mybatis.plus.entity.order.CheckOrder;
import com.mybatis.plus.mapper.order.CheckOrderMapper;
import com.mybatis.plus.service.CheckOrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.HashMap;
import java.util.List;

@Service
public class CheckOrderServiceImpl extends ServiceImpl<CheckOrderMapper, CheckOrder> implements CheckOrderService{

    @Autowired
    private CheckOrderMapper checkOrderMapper;

    @Override
    public List<HashMap<String,String>> invokeSql(String sqlString) {
        return checkOrderMapper.invokeSql(sqlString);
    }
}

mapper

package com.mybatis.plus.mapper.order;

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

import com.mybatis.plus.entity.order.CheckOrder;
import org.apache.ibatis.annotations.Param;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * <p>描述：阜外盘点单表Mapper接口</p>
 * <p>公司：浙江瑞华康源科技有限公司</p>
 * <p>版权：rivamed-2019</p>
 * @author 官昌洪
 * @since 2019-10-23
 */
public interface CheckOrderMapper extends BaseMapper<CheckOrder> {

    List<HashMap<String,String>> invokeSql(@Param("sqlString") String sqlString);
 }

xml

    <select id="invokeSql" resultType="java.util.HashMap">
       ${sqlString} limit 1000
    </select>

效果演示

浏览器url输入   localhost:8092/checkOrder/download?sqlString=select * from t_fhvc_check_order

导出excel如下

注意：存在数据库中null字段不返回的问题 添加mysql配置 call-setters-on-nulls: true 即可解决

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    jdbc-type-for-null: null
    call-setters-on-nulls: true
  mapper-locations: classpath*:/com/mybatis/**/*Mapper.xml