code: public function echo404($message = 'Api interface not found', $errorId = '404 Not Found', $statusCode = 404)
      {
          $responseData = array(
              'statusCode' => $statusCode,
              'code' => 0,
              'errorId' => $errorId,
              'message' => $message
          );
          return $this->echoData($responseData);
      }
docs: [echo404 输出]
  @author: 桦 <yuchonghua@163.com>
  @DateTime 2017-04-26T18:56:12+0800