java - Unrecoverable exception while generating token using GoogleAuthUtil -

i want use google authentication login in application .for have followed link followed link

my code :

package com.android.mytokengenerator;  import java.io.ioexception;  import com.google.android.gms.auth.googleauthexception; import com.google.android.gms.auth.googleauthutil; import com.google.android.gms.auth.googleplayservicesavailabilityexception; import com.google.android.gms.auth.userrecoverableauthexception; import com.google.android.gms.common.googleplayservicesutil; import com.google.android.gms.common.scopes;  import android.os.asynctask; import android.os.bundle; import android.accounts.account; import android.accounts.accountmanager; import android.app.activity; import android.app.dialog; import android.content.intent; import android.util.log; import android.view.menu;  public class mainactivity extends activity {     string scope = "audience:server:client_id:server client key";     int my_activitys_auth_request_code = 200;@     override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);         new gettoken().execute(null, null, null);      }      @     override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.main, menu);         return true;     }     protected void onactivityresult(int requestcode, int resultcode, intent data) {         if (requestcode == my_activitys_auth_request_code) {             if (resultcode == result_ok) {                 new gettoken().execute(null, null, null);             }         }     }     public class gettoken extends asynctask < void, void, void > {          @         override         protected void doinbackground(void...params) {             // todo auto-generated method stub             getanduseauthtokenblocking();              return null;         }      }     // example of how use googleauthutil in blocking, non-main thread context     void getanduseauthtokenblocking() {          // retrieve token given account , scope. return either         // non-empty string or throw exception.         string[] account = getaccountnames();         (int = 0; < account.length; i++) {             try {                 final string token = googleauthutil.gettoken(mainactivity.this, account[i], "oauth2:" + scopes.plus_profile);                 log.e("token", token);                 // work token.                 //                        if (server indicates token invalid) {                 //                            // invalidate token found bad googleauthutil won't                 //                            // return next time (it may have cached it)                 //                            googleauthutil.invalidatetoken(context, string)(context, token);                 //                            // consider retrying getandusetokenblocking() once more                 //                            return;                 //                        }                 return;             } catch (googleplayservicesavailabilityexception playex) {                 dialog alert = googleplayservicesutil.geterrordialog(                     playex.getconnectionstatuscode(),                     this,                     my_activitys_auth_request_code);              } catch (userrecoverableauthexception userauthex) {                 log.e("userrecoverableauthexception", "userrecoverableauthexception");                 userauthex.printstacktrace();                 // start user recoverable action using intent returned                 // getintent()                 mainactivity.this.startactivityforresult(                     userauthex.getintent(),                     my_activitys_auth_request_code);                 return;             } catch (ioexception transientex) {                 log.e("ioexception", "ioexception");                 transientex.printstacktrace();                  // network or server error, call expected succeed if try again later.                 // don't attempt call again - request                 // fail, you'll hit quotas or back-off.                 return;             } catch (googleauthexception authex) {                 log.e("googleauthexception", "googleauthexception");                 authex.printstacktrace();                  // failure. call not expected ever succeed should not                 // retried.                 return;             } catch (exception e) {                 // todo: handle exception                 e.printstacktrace();             }         }       }     private string[] getaccountnames() {         accountmanager maccountmanager = accountmanager.get(this);         account[] accounts = maccountmanager.getaccountsbytype(             googleauthutil.google_account_type);         string[] names = new string[accounts.length];         (int = 0; < names.length; i++) {             names[i] = accounts[i].name;         }         return names;     } } 

now , when put scope value
string scope = "audience:server:client_id:server client key";
giving exception unknownresource

and when putting value scope string scope = scopes.plus_profile; giving exception

logcat

not getting problem.do need use plusclient connectivity before generating token through googleauthutil.gettoken ().please