用Python显示GAE数据库中的PDF文件

Question

我的Python代码如下：

DEFAULT_GUESTBOOK_NAME = 'default_guestbook'

def guestbook_key(guestbook_name=DEFAULT_GUESTBOOK_NAME):
    return ndb.Key('Guestbook', guestbook_name)

class Author(ndb.Model):
    identity = ndb.StringProperty(indexed=False)
    email = ndb.StringProperty(indexed=False)

class Greeting(ndb.Model):
    author = ndb.StructuredProperty(Author)
    content = ndb.StringProperty(indexed=False)
    date = ndb.DateTimeProperty(auto_now_add=True)
    pdf = ndb.BlobProperty(indexed=False)

class MapPage(webapp2.RequestHandler):
    def get(self):  
        guestbook_name = self.request.get('guestbook_name',
                                         DEFAULT_GUESTBOOK_NAME)
        greetings_query = Greeting.query(
        ancestor=guestbook_key(guestbook_name)).order(-Greeting.date)
        greetings = greetings_query.fetch(10)

        user = users.get_current_user()

        template_values = {
            'user': user,
            'user_mail': user.email(),
            'greetings': greetings,
            'guestbook_name': urllib.quote_plus(guestbook_name),
            'def_name': DEFAULT_GUESTBOOK_NAME
        }

        path = os.path.join(os.path.dirname(__file__), 'mappage.html')
        self.response.out.write(template.render(path, template_values))

class Guestbook(webapp2.RequestHandler):
    def post(self):
        guestbook_name = self.request.get('guestbook_name',
                                      DEFAULT_GUESTBOOK_NAME)
        greeting = Greeting(parent=guestbook_key(guestbook_name))

        if users.get_current_user():
            greeting.author = Author(
                  identity=users.get_current_user().user_id(),
                  email=users.get_current_user().email())

        greeting.content = self.request.get('content')
        greeting.pdf = self.request.get('pdf')
        greeting.put()

        query_params = {'guestbook_name': guestbook_name}
        self.redirect('/mappage?' + urllib.urlencode(query_params))

基本上，类留言簿存储了一个带有内容和pdf的问候语。你知道吗

我的HTML端有这样的代码来上传pdf文件：

<form class="notdef" action="/sign?guestbook_name={{ guestbook_name }}"       method="post" style="display:none" enctype="multipart/form-data">
  <div><textarea name="content" rows="3" cols="60"></textarea></div>
  <br>
  <div><input type="file" name="pdf">
  <hr class="notdef" style="display:none">
  <div><input type="submit" value="Save"></div>
</form>

和要显示的代码：

<blockquote>{{ greeting.content }}</blockquote>
<embed src="{{ greeting.pdf}}" width="500" height="375" type="application/pdf">

但是，我得到一个错误

DjangoUnicodeDecodeError: 'utf8' codec can't decode byte 0xe2 in position 11: invalid continuation byte. You passed in ..... (long string)

如何解决此问题以使pdf可见？其他帖子说{{问候语.pdf}}是字符串格式，但如何更改它以便可以显示PDF？你知道吗

Answer 1

您应该将embed标记的src属性设置为pdf的路径，而不是尝试插入实际的pdf数据。你知道吗