Linkedin API用于分享个人资料

Question

我使用以下代码在linkedin个人资料上发布分享帖。

function share($comment, $title, $url, $imageUrl) {
          $shareUrl     =   $this->base_url . "/v1/people/~/shares";

          $xml = "<share>
                  <comment>$comment</comment>
                  <content>
                     <title>$title</title>
                     <submitted-url>$url</submitted-url>
                     <submitted-image-url>$imageUrl</submitted-image-url>
                  </content>
                  <visibility>
                     <code>anyone</code>
                  </visibility>
                </share>";

          $request = OAuthRequest::from_consumer_and_token($this->consumer, $this->access_token, "POST", $shareUrl);
          $request->sign_request($this->signature_method, $this->consumer, $this->access_token);
          $auth_header = $request->to_header("https://api.linkedin.com");
          if ($debug) {
              echo $xml . "\n";
              echo $auth_header . "\n";
          }
          $response = $this->httpRequest($shareUrl, $auth_header, "POST", $xml);
          return $response;
      }

但我收到此错误

{ "errorCode": 0, "message": "[unauthorized]. The token used in the OAuth request is not valid. consumerKey: 81zzkab8nsixp6", "requestId": "GILZJ3Q4MV", "status": 401, "timestamp": 1473170097823 }
1{ "errorCode": 0, "message": "[unauthorized]. OAU:81zzkab8nsixp6|c89e142b-2525-487c-849d-eeaffca04b09|*01|*01:1473170099:V1l36ga90ipTNGKqmQ4OzUKxfoA=", "requestId": "8QWY8GGCCH", "status": 401, "timestamp": 1473170098235 }

任何人都可以帮忙解决这个错误吗？