I'm trying to authorize the Google Play Android Developer API. I'm at the step where I need to make an HTTP post request to exchange the authorization code for an access token and a refresh token. Google gives the following example request:
POST /o/oauth2/token HTTP/1.1
Host: accounts.google.com
Content-Type: application/x-www-form-urlencoded
code=4/v6xr77ewYqhvHSyW6UJ1w7jKwAzu&
client_id=8819981768.apps.googleusercontent.com&
client_secret={client_secret}&
redirect_uri=https://oauth2-login-demo.appspot.com/code&
grant_type=authorization_code
I'm confused... First of all, for an installed application (Android) no client_secret is given. I created a web application for the same project in the Google API Console and this gave me a client_secret, so I used that, even though there is no web application. The following code gives me an "invalid_grant" error:
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("https://accounts.google.com/o/oauth2/token");
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(5);
nameValuePairs.add(new BasicNameValuePair("code", "CODE"));
nameValuePairs.add(new BasicNameValuePair("client_id", "CLIENT_ID"));
nameValuePairs.add(new BasicNameValuePair("client_secret", "CLIENT_SECRET"));
nameValuePairs.add(new BasicNameValuePair("redirect_uri", "urn:ietf:wg:oauth:2.0:oob"));
nameValuePairs.add(new BasicNameValuePair("grant_type", "authorization_code"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
....
Taking out the client_secret entirely gave me an "invalid_request" error.