public function addFollowUser()
 {
     $request = Request::capture();
     $token = $request->input('token');
     // 被关注人id
     $followUserId = $request->input('userId');
     if ($followUserId == null) {
         return Utility::response_format(Utility::RESPONSE_CODE_Error, '', 'userId不能为空');
     }
     // 用户id
     $userId = AuthController::getUserIdByToken($token);
     if ($userId == null) {
         return Utility::response_format(Utility::RESPONSE_CODE_AUTH_ERROR, '', '认证失败');
     }
     DB::beginTransaction();
     try {
         $follow = UserFollows::create(['user_id' => $userId, 'follow_user_id' => $followUserId]);
         $fans = UserFans::create(['user_id' => $followUserId, 'fans_user_id' => $userId]);
         DB::commit();
         if ($follow == null || $fans == null) {
             return Utility::response_format(Utility::RESPONSE_CODE_Error, '', '关注失败');
         } else {
             return Utility::response_format(Utility::RESPONSE_CODE_SUCCESS, '', '关注成功');
         }
     } catch (Exception $e) {
         DB::rollBack();
         return Utility::response_format(Utility::RESPONSE_CODE_DB_ERROR, '', $e->getMessage());
     }
 }