Google Cloud Messaging HTTP Error 400: Bad Request

Question

I am trying to send a message through GCM (Google Cloud Messaging). I have registered through Google APIs, I can send a regID to my website (which is a Google App Engine Backend) from multiple Android test phones. However, I can't send anything to GCM from Google App Engine. Here is what I am trying to use.

    regId = "APA91b..."

    json_data = {"collapse_key" : "Food-Promo", "data" : {
                    "Category" : "FOOD",
                    "Type": "VEG",
               }, "registration_ids": [regId],
    }


    url = 'https://android.googleapis.com/gcm/send'




    apiKey = "AI..."
    myKey = "key=" + apiKey

    headers = {'Content-Type': 'application/json', 'Authorization': myKey}
    data = urllib.urlencode(json_data)
    data2 = {"title": title}
    data3 = urllib.urlencode(data2)

    req = urllib2.Request(url, data, headers)


    f = urllib2.urlopen(req)
    response = f.read()
    f.close()

    logging.debug("***!!!!!!!WriteEntry TEST -----  Response: " + response)

And here is the error that I am receiving.

Traceback (most recent call last):
  File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/_webapp25.py", line 703, in __call__
    handler.post(*groups)
  File "/base/data/home/apps/s~journaltestza/26.360625174851783344/main.py", line 213, in post
    f = urllib2.urlopen(req)
  File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 124, in urlopen
    return _opener.open(url, data)
  File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 387, in open
    response = meth(req, response)
  File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 498, in http_response
    'http', request, response, code, msg, hdrs)
  File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 425, in error
    return self._call_chain(*args)
  File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 360, in _call_chain
    result = func(*args)
  File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 506, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
HTTPError: HTTP Error 400: Bad Request

Thanks!

Answer 1

What are data2 and data3 used for ? The data you are posting was not proper json so you need to use json.dumps(data).Code should be like this :

json_data = {"collapse_key" : "Food-Promo", "data" : {
                "Category" : "FOOD",
                "Type": "VEG",
           }, "registration_ids": [regId],
}


url = 'https://android.googleapis.com/gcm/send'
apiKey = "AI..."
myKey = "key=" + apiKey
data = json.dumps(json_data)
headers = {'Content-Type': 'application/json', 'Authorization': myKey}
req = urllib2.Request(url, data, headers)
f = urllib2.urlopen(req)
response = json.loads(f.read())
reply = {}
if response ['failure'] == 0:
    reply['error'] = '0'
else:
    response ['error'] = '1'
return HttpResponse(json.dumps(reply), mimetype="application/javascript")

Answer 2

Try using python-gcm. It can handle errors as well.