BlobStore -显示照片错误

Question

我有使用GWT/GAE MySQL云的经验。但我不支持BlobStore。我得把我的项目照片加进去。为了理解BlobStore，我找到了一个例子：https://github.com/ikai/gwt-gae-image-gallery。但不起作用。我有两个问题：

1.为什么servlet“UploadServlet”返回null作为blob键：

public void doPost(HttpServletRequest req, HttpServletResponse res)
        throws ServletException, IOException {
        // Take uploaded image
    Map<String, List<BlobKey>> blobs = blobstoreService.getUploads(req);
    System.out.println("UPL.SERV.key size=" + blobs.size());
    List<BlobKey> blobKey = blobs.get("image");
    ImagesService imagesService = ImagesServiceFactory.getImagesService();
    String imageUrl = imagesService.getServingUrl(ServingUrlOptions.Builder.withBlobKey(blobKey.get(0))).trim();
    // Uploaded image object: key, servingUrl,createdAt, ownerId
    Entity uploadedImage = new Entity("UploadedImage");

    uploadedImage.setProperty("blobKey", blobKey.get(0).getKeyString().trim());
    uploadedImage.setProperty(UploadedImage.CREATED_AT, new Date());
    uploadedImage.setProperty(UploadedImage.OWNER_ID, "anna");

    // Highly unlikely we'll ever search on this property
    uploadedImage.setUnindexedProperty(UploadedImage.SERVING_URL, imageUrl);
    System.out.println("UPL.SERV-5- Z datastore key=" + keyString);
    res.sendRedirect("/upload?uploadedImageKey=" + keyString);
}

key=aglub19hcHBfaWRyGgsSDVVwbG9hZGVkSW1hZ2UYgICAgICA4ggM @ doPost doGet(HttpServletRequest req，HttpServletResponse resp)抛出ServletException，IOException {

    System.out.println("UPL.SERV-6- req="+req.getParameter("uploadedImageKey"));
    String uploadedImageKey = req.getParameter("uploadedImageKey").trim();
    resp.setHeader("Content-Type", "text/html");

    // This is a bit hacky, but it'll work. We'll use this key in an Async
    // service to
    // fetch the image and image information
    System.out.println("UPL.SERV-7- resp="+uploadedImageKey);
    resp.getWriter().println(uploadedImageKey);
}

获得: UPL.SERV-6- req=aglub19hcHBfaWRyGgsSDVVwbG9hZGVkSW1hZ2UYgICAgICA4ggM，并将应答发送到“UploadPhoto”：UPL.SERV-7- resp=aglub19hcHBfaWRyGgsSDVVwbG9hZGVkSW1hZ2UYgICAgICA4ggM。

“UploadPhoto获得null。

1. 为什么我不能展示我的照片？

在数据存储中存在：

用于数据存储的UPL.SERV-3集

UPL.SERV-3-BLOBKY=7 7cvGUXW_q9Q9QTEArWv3LA

UPL.SERV-3-KEY=UploadedImage(无id-尚未)

UPL.SERV-3-所有者=anna

UPL.SERV-3-url=q9Q9QTEArWv3LA

UPL.SERV-4-放置到数据存储

当创建了“ImageOverlay”小部件时，我得到：

7cvGUXW_q9Q9QTEArWv3LA=s200:1 GET q9Q9QTEArWv3LA=s200 net::ERR_ADDRESS_INVALID

Answer 1

它不能工作，因为doGet在开发模式下返回null。