java - 当我将图像存储在谷歌驱动器上时如何在我的项目中显示缩略图

Question

我正在成功上传文档并存储在 Google 云端硬盘上。现在我只想获取文档的缩略图以显示在下载链接的位置。请建议我该怎么做？这是我用于上传文档的 Controller 代码。

'`@RequestMapping(value = "/upload", method = RequestMethod.POST)
public ModelAndView uploadFile(@RequestParam(value = "ddid", required = true) Integer ddid,
        @RequestParam(value = "catageryId", required = true) Integer catageryId,
        @RequestParam(value = "document", required = true) GMultipartFile document[], HttpServletRequest request, HttpServletResponse resp) {

    DdeDriveDocuments ddeDriveDocuments = new DdeDriveDocuments();
    if (ServletFileUpload.isMultipartContent(request) && document != null) {
        for (GMultipartFile gdocument : document) {
            try {
                boolean user = true;
                List<DdeDriveDocuments> dds = ddeDriveDocumentsService.fatchData(ddid, catageryId);
                for (DdeDriveDocuments file : dds) {
                    System.out.println(file.getDocument_name());
                    if (file.getDocument_name().equals(gdocument.getOriginalFilename())) {
                        user = false;
                    }
                }

                if (user == true) {
                    ddeDriveDocuments
                            .setDocument_name((gdocument.getName() != null ? gdocument.getOriginalFilename() : ""));
                    System.out.println(gdocument.getOriginalFilename());
                    ddeDriveDocuments.setDocument_created(new Date());
                    ddeDriveDocuments.setCatagery_id(catageryId);
                    ddeDriveDocuments.setDd_id(ddid);
                    ddeDriveDocuments.setDd_uuid(GeneralUtil.getUUID());

                    Lawyer googleAuthToken = lawyerService
                            .getAuthorisedUserToken(Configurator.getInstance().getDriveAccountEmail());
                    if (googleAuthToken != null) {
                        // upload file in drive
                        if (ServletFileUpload.isMultipartContent(request) && document != null) {

                            // It's value either we need to get from form.
                            String description = "Testing";

                            File file = DriveService.uploadDocumentToDrive(googleAuthToken, gdocument,
                                    ddeDriveDocuments.getDocument_name(), description);



                                File thumFile = DriveService.getFileById(googleAuthToken, file.getId());

                                System.out.println("thab url"+thumFile.getThumbnail());

                            System.out.println(file.getThumbnailLink());



                            if (file != null) {
                                ddeDriveDocuments.setDocument_drive_id(file.getId());
                                ddeDriveDocuments.setThumburl(thumFile.getThumbnailLink());
                                ddeDriveDocuments = ddeDriveDocumentsService.create(ddeDriveDocuments);
                            }
                        }
                    } else {
                        System.out.println("Autorised token not available for configured drive account.");
                    }

                }

                else {
                    System.out.println("wroung Input");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    return new ModelAndView("redirect:/al/lawyer/ddfiles/" + ddid + "/" + catageryId);
}`'

Answer 1

您必须使用 Drive REST API 方法 Files: get 。该方法的结果包含 thumbnailLink 但根据 documentation它是“指向文件缩略图的短暂链接”。通常持续几个小时。”

或者，如果您只是想显示一些漂亮的内容，您可以获取文件的内容类型或扩展名，并显示该类型的所有文件的通用缩略图。我建议这样做是因为根据我的经验，驱动器 api 不是响应速度快的 api 之一。

或者或者另外，您可以/应该在应用程序中缓存缩略图，减少驱动器 api 请求的数量，从而提高页面性能。