案例一

    @ApiOperation(value = "根据id 批量下载文件", notes = "根据id 批量下载文件")

    @RequestMapping(value = "/downloadFiles/{id}", method = RequestMethod.GET)

    @ApiImplicitParam(name = "sheetId", value = "工单ID", required = true, dataType = "String", paramType = "path")

    public void downloadFiles(HttpServletRequest request, HttpServletResponse response, @PathVariable String id) throws Exception {

        List<OssMediaFile> list = null;

        try {

            EntityWrapper<OssMediaFile> wrapper = new EntityWrapper<>();

            wrapper.eq("id", id);

            wrapper.eq("is_delete", 0);

            list = this.baseService.selectList(wrapper);

            response.setContentType("text/html;charset=UTF-8");

            request.setCharacterEncoding("UTF-8");

            String header = request.getHeader("User-Agent").toUpperCase();

            String fileName = "附件" + String.valueOf(System.currentTimeMillis()) + ".zip";

            if (!header.contains("MSIE") && !header.contains("TRIDENT") && !header.contains("EDGE")) {

                fileName = new String(fileName.getBytes(), "ISO8859-1");

            } else {

                fileName = URLEncoder.encode(fileName, "utf-8");

                fileName = fileName.replace("+", "%20");

            }

            response.setContentType("multipart/form-data");

            response.setHeader("Content-disposition", "attachment; filename=" + fileName);

        } catch (Exception e) {

            logger.error(e.getMessage(), e);

        }

        try(ZipOutputStream zipOut = new ZipOutputStream(response.getOutputStream())) {

            for (int i = 0; i < list.size(); i++) {

                OssMediaFile mediaFile = list.get(i);

                logger.info("ossMediaFile参数：{}", JSONObject.toJSONString(mediaFile));

                InputStream is = null;

                try {

                    zipOut.putNextEntry(new ZipEntry(mediaFile.getFileName()));

                    String urlName = mediaFile.getFileUrl();

                    URL url = new URL(urlName);

                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();

                    // 设置是否向HttpURLConnection输出

                    conn.setDoOutput(false);

                    // 设置是否从httpUrlConnection读入

                    conn.setDoInput(true);

                    /** 设置连接方式：GET */

                    conn.setRequestMethod("GET");

                    /** 设置连接主机服务器超时时间：5000毫秒 */

                    conn.setConnectTimeout(5000);

                    /** 发送GET方式请求，使用connet方法建立和远程资源之间的实际连接即可 */

                    conn.connect();

                    int status = conn.getResponseCode();

                    logger.info("---status：" + status);

                    if(status!= HttpURLConnection.HTTP_OK){

                        is = conn.getErrorStream();

                    }else{

                        is = conn.getInputStream();

                    }

                    if (null == is) {

                        continue;

                    }

                    int temp = 0;

                    while ((temp = is.read()) != -1) {

                        zipOut.write(temp);

                    }

                    is.close();

                    /** 关闭远程连接 */

                    conn.disconnect();

                } catch (IOException e) {

                    logger.error(e.getMessage(), e);

                }

            }

            zipOut.closeEntry();

            logger.info("一键下载结束");

        } catch (Exception e) {

            logger.error(e.getMessage(), e);

            throw new RuntimeException("附件下载失败");

        }

    }