成功登录后如何获取谷歌访问令牌？

Question

我需要在成功登录后从Google获取访问令牌。我使用下面的代码但我收到此错误（[ERROR] IO Exception: java.io.IOException: NetworkError）。请任何人帮助我。

try {

                         token = GoogleAuthUtil.getToken(
                                 DoctorDetailsActivity.this,                             // Context context
                                 accountName,     // String accountName
                                    "http://www.google.com/m8/feeds/"
                                );

                    } catch (IOException transientEx) {
                      // network or server error, the call is expected to succeed if you try again later.
                      // Don't attempt to call again immediately - the request is likely to
                      // fail, you'll hit quotas or back-off.
                        Log.e("getAccessToken()", "[ERROR] IOException: " + transientEx);
                    } catch (UserRecoverableAuthException e) {
                           // Recover
                        Log.e("getAccessToken()", "[ERROR] UserRecoverableAuthException: " + e);

                    } catch (GoogleAuthException authEx) {
                      // Failure. The call is not expected to ever succeed so it should not be
                      // retried.
                        Log.e("getAccessToken()", "[ERROR] GoogleAuthException: " + authEx);
                    } catch (Exception e) {
                        Log.e("getAccessToken()", "[ERROR] Exception: " + e);
                      throw new RuntimeException(e);
                    }