Question

I am not very familiar with programming with requests so I’m going to try to be as concise and I possibly can in describing my problem.

I am trying to get an authentication token which I can use to get a Google account’s userinfo.
I succeeded in getting the token in this form: https://oauth2-login-demo.appspot.com/oauthcallback#access_token={accesstoken}&token_type=Bearer&expires_in=3600

Then I followed this tutorial’s TODO#11: http://www.sw-engineering-candies.com/blog-1/howtogetuserinformationwithoauth2inagwtandgoogleappenginejavaapplication

@Override
public LoginInfo loginDetails(final String token) {
    String url = "https://www.googleapis.com/oauth2/v1/userinfo?alt=json&access_token=" 
        + token;

    final StringBuffer r = new StringBuffer();
    try {
        final URL u = new URL(url);
        final URLConnection uc = u.openConnection();
        final int end = 1000;
        InputStreamReader isr = null;
        BufferedReader br = null;
        try {
            isr = new InputStreamReader(uc.getInputStream());
            br = new BufferedReader(isr);
            final int chk = 0;
            while ((url = br.readLine()) != null) {
                if ((chk >= 0) && ((chk < end))) {
                    r.append(url).append('\n');
                }
            }
        } catch (final java.net.ConnectException cex) {
            r.append(cex.getMessage());
        } catch (final Exception ex) {
            log.log(Level.SEVERE, ex.getMessage());
        } finally {
            try {
                br.close();
            } catch (final Exception ex) {
                log.log(Level.SEVERE, ex.getMessage());
            }
        }
    } catch (final Exception e) {
        log.log(Level.SEVERE, e.getMessage());
    }

    final LoginInfo loginInfo = new LoginInfo();
    try {
        final JsonFactory f = new JsonFactory();
        JsonParser jp;
        jp = f.createJsonParser(r.toString());
        jp.nextToken();
        while (jp.nextToken() != JsonToken.END_OBJECT) {
            final String fieldname = jp.getCurrentName();
            jp.nextToken();
            if ("picture".equals(fieldname)) {
                loginInfo.setPictureUrl(jp.getText());
            } else if ("name".equals(fieldname)) {
                loginInfo.setName(jp.getText());
            } else if ("email".equals(fieldname)) {
                loginInfo.setEmailAddress(jp.getText());
            }
        }
    } catch (final JsonParseException e) {
        log.log(Level.SEVERE, e.getMessage());
    } catch (final IOException e) {
        log.log(Level.SEVERE, e.getMessage());
    }
    return loginInfo;
}

When that code is run, I am catching an error:

WARNING: Authentication error: Unable to respond to any of these challenges: {googlelogin=WWW-Authenticate: GoogleLogin realm="https://www.google.com/accounts/ClientLogin", service="lso"}
{
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "required",
    "message": "Login Required",
    "locationType": "header",
    "location": "Authorization"
   }
  ],
  "code": 401,
  "message": "Login Required"
 }
}

I am running in development mode in GWT. I also tried deploying and running, but it also caught some error.

Some possible causes could be:
1) my token timed out (but I Just got it)
2) I must deploy first?
3) I’m not doing the steps properly? (after i get the token, I have to validate it first? how do i do that?)

I am not quite sure how to proceed from here. Hoping to get some help from the community.

Answer 1

It was a string concatenation error. The variable wasn’t holding a valid token.