一、依赖

<dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.12</version>
        </dependency>
        <!--解析excel-->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.12</version>
        </dependency>

二、代码

package com.example.demo.test;

import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import java.io.OutputStream;


/**
 * @author xuhc7
 * @date 2021年12月15日 14:14
 */
@Controller
public class ExcelExecute {
    @GetMapping("/upload")
    @ResponseBody
    public void  upload(MultipartFile file, OutputStream outputStream) throws Exception{
        HSSFWorkbook workbook=new HSSFWorkbook();//这里也可以设置sheet的Name
        //创建工作表对象
        HSSFSheet sheet = workbook.createSheet();
        //创建工作表的行
        HSSFRow row = sheet.createRow(0);//设置第一行，从零开始
        row.createCell(2).setCellValue("aaaaaaaaaaaa");//第一行第三列为aaaaaaaaaaaa
        row.createCell(0).setCellValue("33333333333");//第一行第一列为33333333333
        workbook.write(outputStream);
        outputStream.flush();
        outputStream.close();

    }
    
}

三、postman测试结果，导出excel成功