如何在GoogleAppEngineJava中将文件包装为blob并将其提交为数据存储

我尝试使用文件服务将数据存储在Google app engine中，并成功上传了它，但后来我注意到它没有存储为blob值。所以我在谷歌上找到了这个由谷歌提供的链接

在本文件中，代码如下所示：

 FileItemIterator iterator = upload.getItemIterator(req);
 while (iterator.hasNext()) {
 FileItemStream item = iterator.next();
 InputStream stream = item.openStream();
 if (item.isFormField()) {
 log.warning("Got a form field: " + item.getFieldName());
 } else {
 log.warning("Got an uploaded file: " + item.getFieldName() +", name = " + item.getName());

 // You now have the filename (item.getName() and the
 // contents (which you can read from stream). Here we just
 // print them back out to the servlet output stream, but you
 // will probably want to do something more interesting (for
 // example, wrap them in a Blob and commit them to the
 // datastore).

---

这里我不理解如何将它们包装为blob并提交到数据存储。谁能建议我怎么解决这个问题吗。这种方式是否将文件作为blob值存储在google app engine中？

这种方式是将文件作为blob值存储还是作为blobstore中的文件存储？但是我需要将文件作为blob值存储。您能告诉我如何在不使用

createUploadURL

表单操作属性的情况下实现它吗？只需创建db实体并向其添加字节数组属性即可。FileServiceFactory现在是已弃用：（这是将文件存储为blob值还是存储为blob存储中的文件？但我需要存储为blob值您能告诉我如何在不使用

createUploadURL

表单操作属性的情况下实现它吗？只需创建db实体并向其添加字节数组属性。FileServiceFactory现在已弃用：(

InputStream is = item.openStream();
try {
   FileService fileService = FileServiceFactory.getFileService();
   AppEngineFile file = fileService.createNewBlobFile(mime, fileName);
   boolean lock = true;
   FileWriteChannel writeChannel = fileService.openWriteChannel(file, lock);
   byte[] buffer = new byte[BUFFER_SIZE];
   int readBytes;
   while ((readBytes = is.read(buffer)) != -1) {
       writeChannel.write(ByteBuffer.wrap(buffer, 0, readBytes));
   }
   writeChannel.closeFinally();
   String blobKey = fileService.getBlobKey(file).getKeyString();
} catch (Exception e) {
   e.printStackTrace(resp.getWriter());
}