Java

Google Photos OAuth2 Access Token

See more Google Photos Examples

Demonstrates how to get a Google Photos OAuth2 access token from a desktop application or script. Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    CkOAuth2 oauth2 = new CkOAuth2();

    //  For Google OAuth2, set the listen port equal to the port used
    //  in the Authorized Redirect URL for the Client ID.
    //  For example, in this case the Authorized Redirect URL would be http://localhost:3017/
    //  Your app should choose a port not likely not used by any other application.
    oauth2.put_ListenPort(3017);

    oauth2.put_AuthorizationEndpoint("https://accounts.google.com/o/oauth2/v2/auth");
    oauth2.put_TokenEndpoint("https://www.googleapis.com/oauth2/v4/token");

    //  Replace these with actual values.
    oauth2.put_ClientId("GOOGLE-CLIENT-ID");
    oauth2.put_ClientSecret("GOOGLE-CLIENT-SECRET");

    oauth2.put_CodeChallenge(true);
    oauth2.put_CodeChallengeMethod("S256");

    //  This is a scope for Google Photos.  See https://developers.google.com/photos/library/guides/authentication-authorization
    //  This scope provides read/write access but not sharing.
    oauth2.put_Scope("https://www.googleapis.com/auth/photoslibrary");

    //  Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    String url = oauth2.startAuth();
    if (oauth2.get_LastMethodSuccess() == false) {
        System.out.println(oauth2.lastErrorText());
        return;
        }

    //  Launch the system's default browser navigated to the URL.
    success = oauth2.LaunchBrowser(url);
    if (success == false) {
        System.out.println(oauth2.lastErrorText());
        return;
        }

    //  Now wait for the authorization.
    //  We'll wait for a max of 120 seconds.
    int numMsWaited = 0;
    while ((numMsWaited < 120000) && (oauth2.get_AuthFlowState() < 3)) {
        oauth2.SleepMs(100);
        numMsWaited = numMsWaited+100;
        }

    //  If there was no response from the browser within 120 seconds, then 
    //  the AuthFlowState will be equal to 1 or 2.
    //  1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
    //  2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
    //  In that case, cancel the background task started in the call to StartAuth.
    if (oauth2.get_AuthFlowState() < 3) {
        oauth2.Cancel();
        System.out.println("No response from the browser!");
        return;
        }

    //  Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
    //  The possible AuthFlowState values are:
    //  3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
    //  4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
    //  5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
    if (oauth2.get_AuthFlowState() == 5) {
        System.out.println("OAuth2 failed to complete.");
        System.out.println(oauth2.failureInfo());
        return;
        }

    if (oauth2.get_AuthFlowState() == 4) {
        System.out.println("OAuth2 authorization was denied.");
        System.out.println(oauth2.accessTokenResponse());
        return;
        }

    if (oauth2.get_AuthFlowState() != 3) {
        System.out.println("Unexpected AuthFlowState:" + oauth2.get_AuthFlowState());
        return;
        }

    //  Save the full JSON access token response to a file.
    CkStringBuilder sbJson = new CkStringBuilder();
    sbJson.Append(oauth2.accessTokenResponse());
    sbJson.WriteFile("qa_data/tokens/googlePhotos.json","utf-8",false);

    //  The saved JSON response looks like this:
    //  {
    //    "access_token": "ya29.GlamBqWR6cp8lEfJMmTHVEua45912XLKoq4djyHl_Z3CEIzsPLIZkJSGie5oOrbaggy1rjJHn1zW5bjqSesGr5MEYIp9Hx-0CuvjVYf8srg2jeaDMwMACvzemp43",
    //    "expires_in": 3600,
    //    "refresh_token": "1/rl6k16nysDl9Bp1EhRH9F1WyRIoiSQAvko49Z4yY694MT5V1QXLj2ibNZGaRgek0",
    //    "scope": "https://www.googleapis.com/auth/photoslibrary",
    //    "token_type": "Bearer"
    //  }

    System.out.println("OAuth2 authorization granted!");
    System.out.println("Access Token = " + oauth2.accessToken());
  }
}