Google OAuth 2 is generating redirect_uri instead of using one defined in client_secret.json - google-api

Question

I would like to use the Google Calendar API, but in order to do that, I need to be authorized using Googles OAuth 2.0 API. I am running into trouble with the redirect_uri. The following is a sample of my client_secret.json.
{
"web": {
"client_id": "deleted",
"client_secret": "deleted",
"redirect_uris": ["http://localhost:8080/CommunityUmcPasadena/Callback"],
"auth_uri": "https://accounts.google.com/o/oauth2/auth",
"token_uri": "https://accounts.google.com/o/oauth2/token"
}
}
When I run my Quickstart application, I get the following error:
Apr 20, 2017 10:45:42 PM com.google.api.client.util.store.FileDataStoreFactory setPermissionsToOwnerOnly
WARNING: unable to change permissions for everybody: C:\Users\Gary\.credentials\calendar-java-quickstart
Apr 20, 2017 10:45:42 PM com.google.api.client.util.store.FileDataStoreFactory setPermissionsToOwnerOnly
WARNING: unable to change permissions for owner: C:\Users\Gary\.credentials\calendar-java-quickstart
2017-04-20 22:45:42.485:INFO::Logging to STDERR via org.mortbay.log.StdErrLog
2017-04-20 22:45:42.485:INFO::jetty-6.1.26
2017-04-20 22:45:42.498:INFO::Started SocketConnector#localhost:34940
Please open the following address in your browser:
https://accounts.google.com/o/oauth2/auth?access_type=offline&client_id=deleted&redirect_uri=http://localhost:34940/Callback&response_type=code&scope=https://www.googleapis.com/auth/calendar.readonly
Attempting to open that address in the default browser now...
As you can see, it has the redirect_uri as http://localhost:34940/Callback. This is not what is defined in client_secret.json though. It is using the correct client_id and secret though. Therefore, I'm not sure why the api is generating a random callback. I would also like to note that the redirect_uri listed in the client_secret.json is the same as the API Manager.
Does anyone know why the redirect_uri is being generated by the API instead of using the one defined in the client_secret.json?
Any help is greatly appreciated.
Also, here is the code for the quick start application...
package sample;
import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.client.util.DateTime;
import com.google.api.services.calendar.CalendarScopes;
import com.google.api.services.calendar.model.*;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.List;
public class Quickstart {
private static final String APPLICATION_NAME = "Google Calendar API Java Quickstart";
private static final java.io.File DATA_STORE_DIR = new java.io.File(System.getProperty("user.home"), ".credentials/calendar-java-quickstart");
private static FileDataStoreFactory DATA_STORE_FACTORY;
private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();
private static HttpTransport HTTP_TRANSPORT;
private static final List<String> SCOPES = Arrays.asList(CalendarScopes.CALENDAR_READONLY);
static {
try {
HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
DATA_STORE_FACTORY = new FileDataStoreFactory(DATA_STORE_DIR);
}
catch(Throwable t) {
t.printStackTrace();
System.exit(1);
}
}
public static Credential authorize() throws IOException {
InputStream in = Quickstart.class.getResourceAsStream("/client_secret.json");
GoogleClientSecrets clientSecrets =
GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));
GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
.setDataStoreFactory(DATA_STORE_FACTORY).setAccessType("offline").build();
Credential credential = new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
System.out.println("Credentials saved to " + DATA_STORE_DIR.getAbsolutePath());
return credential;
}
public static com.google.api.services.calendar.Calendar getCalendarService() throws IOException {
Credential credential = authorize();
return new com.google.api.services.calendar.Calendar.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential)
.setApplicationName(APPLICATION_NAME)
.build();
}
public static void main(String[] args) throws IOException {
com.google.api.services.calendar.Calendar service = getCalendarService();
}
}

Answer 1

Your code doesn't specify a redirect_url. I suspect that the Java library is making the assumption that if you don't specify a redirect_url, it's because you don't have one, so it defaults to a fake URL. It looks like you've copy/pasted the Quickstart code which says at the top of the page "a simple Java command-line application", whereas I think you're building a web server application.
Sooo, dig into the Java OAuth library docs (good luck - try https://developers.google.com/api-client-library/java/google-oauth-java-client/reference/1.20.0/com/google/api/client/auth/oauth2/AuthorizationCodeFlow) and see where to set the redirect URL to your ttp://localhost:8080/CommunityUmcPasadena/Callback

Answer 2

I have been looking an answer for quite some time...
You need to use
LocalServerReceiver
Example usage:
LocalServerReceiver localServerReceiver = new LocalServerReceiver.Builder().setHost("localhost").setPort(8181).build();
Credential credential = new AuthorizationCodeInstalledApp(flow, localServerReceiver).authorize("user");