Java lightweight way to trade request- for access token at google

Question

I get the request token via browser Javascript.

The following Java code works trading it for an access token.

import com.google.api.client.googleapis.auth.oauth2.GoogleTokenResponse;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeTokenRequest;

GoogleTokenResponse tokenResponse = new GoogleAuthorizationCodeTokenRequest(TRANSPORT, JSON_FACTORY, clientId, clientSecret, authCode, "postmessage").execute();

My problem is that the google library call comes with fairly heavy footprint.

Hence, I tried scribe (the Kobee1203 oauth 2.0 fork). It did not work for me:

  OAuthService service = new ServiceBuilder()
                                .provider(GoogleApi20.class)
                                .apiKey(apiKey)
                                .apiSecret(apiSecret)
                                .scope(SCOPE)
                                .grantType(OAuthConstants.GRANT_TYPE_AUTHORIZATION_CODE)
                                .accessType("offline")
                                .build();
  Verifier verifier = new Verifier(authcode);
  Token accessToken = service.getAccessToken(null, verifier);

Google response with and error complaining about and indirect redirect url. There is no redirect url set in the api console and the former code works fine without.

I'd like a lightweight Java based solution trading the request- for an access token to make one basic authorized call. It does not necessarily have to be scribe.

Answer 1

It's just a REST URL that you can construct and call directly from your app.

If you go through the steps in the Oauth Playground https://developers.google.com/oauthplayground you can see the URLs and responses. For example, to convert the auth code to a refresh token, you would call

POST /o/oauth2/token HTTP/1.1
Host: accounts.google.com
Content-length: 250
content-type: application/x-www-form-urlencoded
user-agent: google-oauth-playground
code=4%2FcQ7Nh2AZL3QgfynGKSloFTND3hlv.8jT4Txflqs8WXE-sT2ZLcbQTyOPFgQI&redirect_uri=https%3A%2F%2Fdevelopers.google.com%2Foauthplayground&client_id=407408718192.apps.googleusercontent.com&scope=&client_secret=************&grant_type=authorization_code

The URLs and responses are documented at https://developers.google.com/accounts/docs/OAuth2