Question

我已成功使用提供的代码here将图像上传到我的Google App Engine Blobstore（其中一条评论主要基于GAE文档）。

以下是完整的参考代码：

import os
import urllib

from google.appengine.ext import blobstore
from google.appengine.ext import webapp
from google.appengine.ext.webapp import blobstore_handlers
from google.appengine.ext.webapp import template
from google.appengine.ext.webapp.util import run_wsgi_app

class MainHandler(webapp.RequestHandler):
    def get(self):
        upload_url = blobstore.create_upload_url('/upload')
        self.response.out.write('<html><body>')
        self.response.out.write('<form action="%s" method="POST" enctype="multipart/form-data">' % upload_url)
        self.response.out.write("""Upload File: <input type="file" name="file"><br> <input type="submit" name="submit" value="Submit"> </form></body></html>""")

        for b in blobstore.BlobInfo.all():
            self.response.out.write('<li><a href="/serve/%s' % str(b.key()) + '">' + str(b.filename) + '</a>')

class UploadHandler(blobstore_handlers.BlobstoreUploadHandler):
    def post(self):
        upload_files = self.get_uploads('file')
        blob_info = upload_files[0]
        self.redirect('/')

class ServeHandler(blobstore_handlers.BlobstoreDownloadHandler):
    def get(self, blob_key):
        blob_key = str(urllib.unquote(blob_key))
        if not blobstore.get(blob_key):
            self.error(404)
        else:
            self.send_blob(blobstore.BlobInfo.get(blob_key), save_as=True)

def main():
    application = webapp.WSGIApplication(
          [('/', MainHandler),
           ('/upload', UploadHandler),
           ('/serve/([^/]+)?', ServeHandler),
          ], debug=True)
    run_wsgi_app(application)

if __name__ == '__main__':
  main()

但是，此代码要求在包含图像数据的GET请求之前的POST请求中创建上传网址：

def get(self):
  upload_url = blobstore.create_upload_url('/upload')

当我尝试从移动设备发送图像时，我想将服务器代码推送到def post(self):函数下的单个代码块中，而我在执行此操作时遇到了麻烦。

将上述行移到def post(self):代码似乎没有办法。

有什么想法吗？

干杯！布雷特

Answer 1

是的，您可以使用urlfetch将其设为一个代码块。这是我的方法：

class UploadHandler(blobstore_handlers.BlobstoreUploadHandler):
    def post(self):
        upload_files = self.get_uploads('file')
        if len(upload_files) > 0 :
            blob_info = upload_files[0]
            self.response.write(str(blob_info.key()))
        else:
            self.error(404) 

class SomeHandler(webapp.RequestHandler):
    def post(self):
        file = self.request.POST.get('file')
        if (file is not None):
            # Use urlfetch to call to the blob upload url and get result
            # Just copy the same request body and header and pass to UploadHandler here
            result = urlfetch.fetch(
                url= blobstore.create_upload_url('/upload'),
                payload=self.request.body,
                method=urlfetch.POST,
                headers=self.request.headers)
            if result.status_code == 200:
                blob_key_str = result.content
                # Get blob key
                blob_key = blobstore.BlobKey(blob_key_str)
                # Maybe a url for the file
                blob_url = images.get_serving_url(blob_key_str, 400)

通过这种方式，您始终可以将文件上传到SomeHandler，而不必先获取上传网址，然后才能获取上传。

希望它有所帮助！

Answer 2

这不适用于默认的Blobstore上传处理程序：它需要两个请求：首先创建一次性下载URL，第二个实际对此URL进行POST。

如果您想一次性完成所有操作，请创建自己的file upload handler并使用新的Blobstore API到write files。

GAE - 将图像从移动设备上传到blobstore

2 个答案: