我想象使用 blobstore 存储图像的过程以将 blob 键保存在数据存储区中结束。所以在下面的代码中,它应该在我的后端,为什么我需要一个重定向 URL,因为我已经有了 blob 键?为什么我不只是将 blob 密钥保存在我的数据存储中然后返回它?
public class Upload extends HttpServlet {
private BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService();
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
Map<String, BlobKey> blobs = blobstoreService.getUploadedBlobs(req);
BlobKey blobKey = blobs.get("myFile");
if (blobKey == null) {
res.sendRedirect("/");
} else {
res.sendRedirect("/serve?blob-key=" + blobKey.getKeyString());
}
}
}
此代码来自教程:https ://developers.google.com/appengine/docs/java/blobstore/overview#Complete_Sample_App