浏览器中的图像缓存 - app-engine-patch应用程序

Question

我在浏览器中为我的app-engine应用程序缓存图像时遇到一些问题我发送了最后修改过的,过期的和缓存控制标题,但每次都从服务器加载图像.这是代码的标题部分:

响应['Content-Type'] ='image/jpg'

response ['Last-Modified'] = current_time.strftime('%a,%d%b%Y%H:%M:%S GMT')

响应['Expires'] = current_time + timedelta(天= 30)

response ['Cache-Control'] ='public,max-age = 2592000'

Answer 1

下面是在dpaste我修复副本的示例代码这里

def view_image(request, key):
  data = memcache.get(key)  
  if data is not None:  
    if(request.META.get('HTTP_IF_MODIFIED_SINCE') >= data['Last-Modified']):  
      data.status_code = 304  
    return data  
  else:  
    image_content_blob = #some code to get the image from the data store  
    current_time = datetime.utcnow()
    response = HttpResponse()
    last_modified = current_time - timedelta(days=1)
    response['Content-Type'] = 'image/jpg'
    response['Last-Modified'] = last_modified.strftime('%a, %d %b %Y %H:%M:%S GMT')
    response['Expires'] = current_time + timedelta(days=30)
    response['Cache-Control']  = 'public, max-age=315360000'
    response['Date']           = current_time
    response.content = image_content_blob

    memcache.add(image_key, response, 86400)
    return response