实现excle文件的导入和导出

 @RequestMapping("/export")
    public void export(HttpServletResponse response){
        try {
            List<User> list=userMapper.findAll();
            ExcelWriter excelWriter= ExcelUtil.getWriter(true);
            excelWriter.write(list,true);
            //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
            String filename= null;
            filename = URLEncoder.encode("用户信息","UTF-8");
            response.setHeader("Content-Disposition","attachment;filename="+filename+".xls");
            ServletOutputStream out = response.getOutputStream();
            excelWriter.flush(out, true);
            // 关闭writer，释放内存
            excelWriter.close();
            //此处记得关闭输出Servlet流
            IoUtil.close(out);
        } catch (Exception e){
            e.printStackTrace();
        }
    }
    @RequestMapping("/import")
    public Boolean imports(MultipartFile file){
        try {
            InputStream inputStream=file.getInputStream();
            ExcelReader excelReader=ExcelUtil.getReader(inputStream);
            List<User> list=excelReader.readAll(User.class);
            for (User u :
                    list) {
                userMapper.addUser(u);
            }
            System.out.println(list);
            return true;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return false;
    }

<dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.23</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.1.2</version>
</dependency>