android - Gmail API: Authentication using token retrieval -

i have read whole article authentication using oauth2.0. didn't find suitable method on android application. please suggest method access token can build gmail service object , access inbox or other method.

this example given them in link:

googlecredential credential = new googlecredential().setaccesstoken(accesstoken); plus plus = new plus.builder(new nethttptransport(), jacksonfactory.getdefaultinstance(), credential)     .setapplicationname("google-plussample/1.0")     .build(); 

invoke below method token , google account used in mobile. method first retrieves google account setup in mobile , later retrieves token. can save token , account name using preferences later use dont have retrieve token each time.

private void chooseaccount() {         intent intent = accountpicker.newchooseaccountintent(null, null,                 new string[]{"com.google"}, false, null, null, null, null);         startactivityforresult(intent, 9009);     } 

after account retrieved below method called,

public static final string mail_google_com = "https://mail.google.com"; public static final string gmail_compose = "https://www.googleapis.com/auth/gmail.compose"; public static final string gmail_modify = "https://www.googleapis.com/auth/gmail.modify"; private static final string scope = "oauth2:" + gmail_compose + " " + gmail_modify + " " + mail_google_com;  @override     public void onactivityresult(int requestcode, int resultcode, intent data) {         super.onactivityresult(requestcode, resultcode, data);         if (resultcode == activity.result_ok) {             string accountname = data.getstringextra(accountmanager.key_account_name);             //accountname - google account in mobile retrieved             //now use google account retrieve token             new gettoken(getactivity().getapplicationcontext(), scope, accountname).execute();             showerrordialog(exception);             }         } else if (requestcode == activity.result_canceled) {             toast.maketext(getactivity(), "cancelled!!!", toast.length_short).show();         }     } 

below class used token.

private class gettoken extends asynctask<void, void, void> {     context context;     string mscope, memail, token;      gettoken(context context, string scope, string email) {         this.context = context;         this.mscope = scope;         this.memail = email;     }      @override     protected void doinbackground(void... params) {         try {             token = googleauthutil.gettoken(context, memail, mscope);             //save token using preference later use or stuff using token here             log.v("ranjapp", "token " + token);         } catch (userrecoverableauthexception e) {             handleexception(e);         } catch (googleauthexception ex) {             handleexception(ex);         } catch (exception e) {             //display error dialog         }         return null;     }      void handleexception(final exception e) {         getactivity().runonuithread(new runnable() {             @override             public void run() {                 if (e instanceof userrecoverableauthexception) {                     intent intent = ((userrecoverableauthexception) e).getintent();                     startactivityforresult(intent, 10098);                 } else if (e instanceof googleplayservicesavailabilityexception) {                     int statuscode = ((googleplayservicesavailabilityexception) e)                             .getconnectionstatuscode();                     dialog dialog = googleplayservicesutil.geterrordialog(statuscode, getactivity(), 10099);                     dialog.show();                 }             }         });     } } 

you have register app in google play console token successfully. ensure have play services setup in app.

to register android app google cloud console:

1. visit google cloud console.
2. if have existing project you're adding android app, select project. otherwise, click create project @ top, enter project name , id, click create. note: name provide project name appears users in google settings app in list of connected apps.
3. in left-side navigation, select apis & auth.
4. enable api you'd use setting status on.
5. in left-side navigation, select credentials.
6. click create new client id or create new key appropriate app.
7. complete form appears filling in android app details. sha1 fingerprint app, run following command in terminal: keytool -exportcert -alias <keystore_alias> -keystore <keystore_path> -list -v example, you're using debug-key eclipse, command looks this: keytool -exportcert -alias androiddebugkey-keystore ~/.android/debug.keystore -list -v keystore password "android".
8. click create.

for more information: https://developer.android.com/google/auth/http-auth.html