@PostMapping("/person")
    public void download(@RequestBody Person person,
                         HttpServletResponse response){
        try {
            response.reset();
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            String fileName ="学生"+ LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
            response.setHeader("Content-disposition",
                    "attachment;filename=" + URLEncoder.encode(fileName,"utf-8")+".xlsx");
            ExcelWriter build = EasyExcelFactory.write()
                    .file(response.getOutputStream())
                    .head(PersonExcelVO.class)
                    .build();
                WriteSheet writeSheet = new WriteSheet();
                writeSheet.setSheetName("sheet1");
                Integer count = personMapper.selectWhiteListCount(person.getName());
                if (count != null && count > 0) {
                    int pageSize = 50000;
                    int total = (int) Math.ceil((double) count / pageSize);
                    for (int i = 0; i < total; i++) {
                        List<Person> persons=
                                personMapper.selectStudent(person.getName(),
                                        i * pageSize,
                                        pageSize);
                        if (CollectionUtils.isNotEmpty(persons)) {
                            build.write(PersonMapping.INSTANCE.convertToList(persons), writeSheet);
                        }
                    }
                } else {
                    build.write(Collections.emptyList(), writeSheet);
                }
                build.close();
                build.finish();
        }catch (Exception e){
           log.error("download person error",e);
        }
    }

           <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>easyexcel</artifactId>
                <version>3.3.3</version>
                <scope>provided</scope>
            </dependency>

 @GetMapping("/download")
    public void productTemplateDownload(HttpServletResponse response) {
        log.info("product template start====");
        OutputStream outputStream = null;
        InputStream inputStream = null;
        try {
            String fileName ="product";
            File file = new File(filePath +"product.xlsx" );
            inputStream = Files.newInputStream(file.toPath());
            response.setContentType("application/octet-stream");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName,"utf-8")+".xlsx");
            // 获取输出流
            outputStream = response.getOutputStream();
            IOUtils.copy(inputStream, outputStream);
            log.info("product template end====");
        } catch (IOException e) {
            log.error("文件下载出错", e);
        } finally {
            IOUtils.closeQuietly(inputStream);
            IOUtils.closeQuietly(outputStream);
        }
    }