Google Calendar API returning "Invalid Credentials" (401) -

i having problems authenticating google calendar api v3 using java client library (google-api-client version 1.13.2-beta, google-api-services-calendar version v3-rev26-1.13.2-beta).

we have marketplace app, , installing app should give required credentials reading (and writing) google calendar events.

we using 2-legged oauth 1.0, hmac, meaning no tokens necessary. trying do, calendar instead of tasks: https://developers.google.com/google-apps/help/articles/2lo-in-tasks-for-marketplace

this error i'm getting google:

com.google.api.client.googleapis.json.googlejsonresponseexception: 401 unauthorized {   "code" : 401,   "errors" : [ {     "domain" : "global",     "location" : "authorization",     "locationtype" : "header",     "message" : "invalid credentials",     "reason" : "autherror"   } ],   "message" : "invalid credentials" } 

we have customers don't use marketplace app, have given our domain appropriate permissions hand, , works fine them. customers marketplace app have problem (using different consumerkey , consumersecret), , leads me believe there nothing wrong code, overlooked somewhere in google setup..

the permissions marketplace app fine.

i have followed every guide find, appropriate our setup (not plenty of them out there though), , far can see i'm doing right thing.

the api key seems correctly set (access calendar api granted). mentioned, works our customers not coming marketplace app, , using same api key.

anyway, here's failing junit test reproduce error:

import java.io.ioexception; import java.util.list;  import org.junit.test;  import com.google.api.client.auth.oauth.oauthhmacsigner; import com.google.api.client.auth.oauth.oauthparameters; import com.google.api.client.http.javanet.nethttptransport; import com.google.api.client.json.jackson.jacksonfactory; import com.google.api.services.calendar.calendar; import com.google.api.services.calendar.calendarrequest; import com.google.api.services.calendar.calendarrequestinitializer; import com.google.api.services.calendar.model.calendarlistentry;  import junit.framework.assert;  public class googleoauthtest {      @test     public void test() {         final string api_key = "...";         final string consumer_key = "...";         final string consumer_key_secret = "...";         final string google_user = "me@mydomain.com";          // 2-lo authorization section         oauthhmacsigner signer = new oauthhmacsigner();         signer.clientsharedsecret = consumer_key_secret;          final oauthparameters oauthparameters = new oauthparameters();         oauthparameters.version = "1";         oauthparameters.consumerkey = consumer_key;         oauthparameters.signer = signer;          calendar service = new calendar.builder(new nethttptransport(), new jacksonfactory(), oauthparameters)                 .setapplicationname("myapp")                 .setcalendarrequestinitializer(new calendarrequestinitializer() {                     @override                     protected void initializecalendarrequest(calendarrequest<?> request) throws ioexception {                         request.setkey(api_key);                     }                 }).build();          try {             com.google.api.services.calendar.calendar.calendarlist.list list = service.calendarlist().list();             list.getunknownkeys().put("xoauth_requestor_id", google_user);             // exception!             list<calendarlistentry> calendarlist = list.execute().getitems();         } catch (ioexception e) {             assert.fail("test failed: " + e.getmessage());         }     } } 

what doing wrong? there wrong code, or there might have missed in google setup?

not sure api key is, have similar code except request initializer :

calendarrequestinitializer initializer = new calendarrequestinitializer() {      @override     protected void initializecalendarrequest(calendarrequest<?> calendarrequest) throws ioexception {         arraymap<string, object> customkeys = new arraymap<string, object>();         customkeys.add("xoauth_requestor_id", email_of_the_user);         calendarrequest.setunknownkeys(customkeys);     } }; 

this works me... hope helps;

update use api key when clicking "register additional apis" link in marketplace -> vendor profile -> app.