CODEWITHSUNDEEP
gmailgoogle-drive-api
user2452027
user2452027

Reputation: 41

How to automate OAuth code retrieval from user in standalone program

Can any one help us to run the URL through java code :

we are trying to upload a file from our local drive to Gmail Drive.

Steps Followed

  1. Generated the URL with the help of Google Developer(API)

    GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
     httpTransport, jsonFactory, CLIENT_ID, CLIENT_SECRET, Arrays.asList(DriveScopes.DRIVE))
     .setAccessType("online")
     .setApprovalPrompt("auto").build();

String url = flow.newAuthorizationUrl().setRedirectUri(REDIRECT_URI).build();

  2. Got the below URL

    https://accounts.google.com/o/oauth2/auth?access_type=online&approval_prompt=auto&client_id=1066028402320.apps.googleusercontent.com&redirect_uri=urn:ietf:wg:oauth:2.0:oob&response_type=code&scope=https://www.googleapis.com/auth/drive

  3. Run the URL in the internet browser

  4. UserID and password is given as an input in the internet browser to get the unique response token

Now as a part of our development we have completed till step 2 and want to automate the steps 3 & 4 using java code. (After generating the URL provided with our UserdId and password we should get the response as unique token.)

Expecting your help on this

Upvotes: 4

Views: 533

Answers (1)

JunYoung Gwak
JunYoung Gwak

Reputation: 2987

I would use the following scenario

  1. Set up local webserver to retrieve code from user's oauth redirect
  2. Set redirect_uri of the flow to be local webserver and get auth url
  3. Open browser of auth url for the user
  4. Retrieve code from local webserver and exchange oauth code

Here are some more details with code.

Set up local webserver to retrieve HTTP request

Here is an example of setting local webserver with NanoHttpd

public class OAuthServer extends NanoHTTPD {
    /**
     * Constructs an HTTP server on given port.
     */
    public DebugServer() {
        super(8080);
    }

    @Override
    public Response serve(String uri, Method method, Map<String, String> header, Map<String, String> parms, Map<String, String> files) {
        bool error = false
        string code = null
        // User rejected approval
        if (parm.containsKey("error")) {
            error = true
        }
        // Here we get the code!
        if (parm.containsKey("code")) {
            code = parm.get("code")
        }
        StringBuilder sb = new StringBuilder();
        sb.append("<html>");
        sb.append("<head><title>Authorization</title></head>");
        sb.append("<body>");
        if (error) {
            sb.append("<h1>User rejected</h1>");
        }
        if (code==null) {
            sb.append("<h1>Unknown Error</h1>");
        }
        else {
            sb.append("<h1>Success</h1>");
        }
        sb.append("</body>");
        sb.append("</html>");
        return new Response(sb.toString());
    }

    public static void main(String[] args) {
        ServerRunner.run(OAuthServer.class);
    }
}

Set redirect_uri of the flow to be local webserver and get auth url

String url = flow.newAuthorizationUrl().setRedirectUri("http://localhost:8080").build();

Open browser of auth url for the user

// open the default web browser for the HTML page
Desktop.getDesktop().browse(url);

Retrieve code from local webserver and exchange oauth code

Now, user will approve OAuth from the web browser and send code to the local webserver we just started. Now that we have the code retrieved from local webserver, we can parse it into int and authenticate and authorize with it!

Hope this helps

Upvotes: 2

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