非常直白，请君自行饮用

//下载excel
    @RequestMapping("/downloadAllAppoint")
    @ResponseBody
    public String reprotRecord(HttpServletResponse response) throws IOException {
        // 文件名称
        String fileName = URLEncoder.encode("刷卡记录.xlsx", "utf-8");
        // 通过response设置Content-Type、Content-Disposition
        response.setContentType("application/vnd.ms-excel");
        response.setHeader("Content-Disposition",
                "attachment;filename*=utf-8'zh_cn'" + fileName);

        //生成workBook
        //	HSSFWorkbook workbook = createWorkbook();
        OutputStream outputStream = null;
        HSSFWorkbook workBook = null;

        try {
            // 获取输出流
            outputStream = response.getOutputStream();
            // 生成workBook
            workBook = downloadAllAppoint();
            workBook.write(outputStream);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //关闭
            if (outputStream != null) {
                outputStream.close();
            }
        }
        return null;
    }
    public HSSFWorkbook downloadAllAppoint() throws IOException {
        ///创建个空白的workbook[name:workbook]
        HSSFWorkbook workbook = new HSSFWorkbook();
        //创建个空白的sheet[name:appoint]
        HSSFSheet sheet = workbook.createSheet("appoint");
        //行
        HSSFRow row;
        //单元格
        HSSFCell cell;
        //创建行循环标签
        int i = 0;
        //创建行
        row = sheet.createRow(i);
        //列名标柱
        cell = row.createCell(0);
        cell.setCellValue("预约编号");
        cell = row.createCell(1);
        cell.setCellValue("预约用户账号");
        cell = row.createCell(2);
        cell.setCellValue("用户名");
        cell = row.createCell(3);
        cell.setCellValue("手机号");
        cell = row.createCell(4);
        cell.setCellValue("预约项目");
        cell = row.createCell(5);
        cell.setCellValue("预约时间");
        cell = row.createCell(6);
        cell.setCellValue("预约状态");

        //查询所有预约信息
        List<Appoint> appointList = appointService.selectAllAppoint();
        //开始循环

        for (Appoint appoint : appointList) {
            i++;
            row = sheet.createRow(i);
            cell = row.createCell(0);
            cell.setCellValue(appoint.getAppoint_id());
            cell = row.createCell(1);
            cell.setCellValue(appoint.getAppoint_userid());
            cell = row.createCell(2);
            cell.setCellValue(appoint.getAppoint_username());
            cell = row.createCell(3);
            cell.setCellValue(appoint.getAppoint_phonenum());
            cell = row.createCell(4);
            cell.setCellValue(appoint.getAppoint_project());
            cell = row.createCell(5);
            cell.setCellValue(appoint.getAppoint_time());
            cell = row.createCell(6);
            cell.setCellValue(appoint.getAppoint_status());
        }
        System.out.println("orderCondition.xls--[status:success]!");
        return workbook;
    }