使用hutool进行导入，导出

1，先引入依赖

<dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.7.18</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.1.2</version>
        </dependency>

2，controller类

package com.green.testlocalhost.controller;

import com.green.testlocalhost.common.Exception.BaseException;
import com.green.testlocalhost.service.ExcelService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @Author zdj
 * @Date 2022/11/25 16:49
 * @Version 1.0
 */
@Api(tags = "excel管理")
@RestController
@RequestMapping("/excelMgmt")
public class ExcelController {
    
    

    /**
     *  excel服务类
     **/
    @Autowired
    private ExcelService excelService;

    /**
     * 处理用户成绩方法
     * @param file
     * @return
     */
    @RequestMapping(value = "/detalUserGradeData", method = RequestMethod.POST)
    @ApiOperation(value = "处理用户成绩方法", notes = "处理用户成绩方法", httpMethod = "POST")
    public void detalUserGradeData(HttpServletResponse response, @RequestParam(value = "file", required = false) @RequestPart("file") MultipartFile file) throws IOException {
    
    
        if (file.getBytes() == null) {
    
    
            throw new BaseException("处理用户信息", "文件不能为空！", null);
        }
        excelService.detalUserGradeData(file, response);
    }
}

3，server类

package com.green.testlocalhost.service;

import cn.hutool.core.collection.CollUtil;
import cn.hutool.poi.excel.ExcelReader;
import cn.hutool.poi.excel.ExcelUtil;
import cn.hutool.poi.excel.ExcelWriter;
import com.green.testlocalhost.vo.User;
import org.springframework.stereotype.Service;
import org.springframework.util.ObjectUtils;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;
import java.util.List;

/**
 * @Author zdj
 * @Date 2022/10/28 17:22
 * @Version 1.0
 */
@Service
public class ExcelService {
    
    

    /**
     * 处理用户成绩方法
     * @param file
     * @return
     */
    public void detalUserGradeData(MultipartFile file, HttpServletResponse response) throws IOException {
    
    
        /********************* 处理excel并封装未集合 *********************/
        // 通过文件获取输入流
        InputStream is = file.getInputStream();
        // 借助hutool读取
        ExcelReader reader = ExcelUtil.getReader(is);
        List<User> userListTemp = reader.read(0, 1, User.class);
        // 创建一个List集合
        List<User> userListResult = CollUtil.newArrayList();
        for (User row : userListTemp) {
    
    
            User user = new User();
            user.setName(row.getName());
            user.setAge(row.getAge());
            user.setChineseGrade(row.getChineseGrade());
            user.setMathGrade(row.getMathGrade());
            userListResult.add(user);
        }

        // 求总成绩
        double chineseSumGrade = userListResult.stream().mapToDouble(User::getChineseGrade).sum();
        double mathSumGrade = userListResult.stream().mapToDouble(User::getMathGrade).sum();
        User user = new User();
        user.setName("总成绩");
        user.setChineseGrade(chineseSumGrade);
        user.setMathGrade(mathSumGrade);
        userListResult.add(user);
        // 到这里，导入就结束了哈，你可以将这个userListResult进行入库处理

        /********************* 将数据导出 *********************/
        String excelName = "处理后的用户信息";
        ExcelWriter writer = null;
        ServletOutputStream out = null;
        try {
    
    
            // 设置数据到输入流
            writer = ExcelUtil.getWriter(true);
            writer.write(userListResult, true);
            // 设置响应头
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml,sheet;charset=utf-8");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(excelName, "UTF-8") + ".xlsx");
            out = response.getOutputStream();
            writer.flush(out, true);
        } catch (Exception e) {
    
    
            e.printStackTrace();
            System.out.println("导出出现异常：" + e.getMessage());
        } finally {
    
    
            // 最后关闭输出流和写入流
            if(!ObjectUtils.isEmpty(writer)) writer.close();
            if(!ObjectUtils.isEmpty(out)) out.close();
        }
    }
}

4，po类

package com.green.testlocalhost.vo;

import cn.hutool.core.annotation.Alias;
import lombok.Data;

/**
 * @Author zdj
 * @Date 2022/11/25 17:02
 * @Version 1.0
 */
@Data
public class User {
    
    
    @Alias("姓名")
    private String name;

    @Alias("年龄")
    private String age;

    @Alias("语文成绩")
    private Double chineseGrade;

    @Alias("数学成绩")
    private Double mathGrade;
}

5,测试

简单粗暴，一步到位（这里偷懒，将导入，导出写在同一个方法中，只是记录下，使用方式，需要的伙伴们，自己进行参照封装下，即可）