public OperationResult CheckAccessToken(string accessToken)
        {
            IFindAccessTokenRepository repo         = (IFindAccessTokenRepository)RepositoryFactory.Create("Find.Tools.OAuthServerManager.AccessToken");
            List <AccessToken>         accessTokens = repo.FindByAccessTokenString(accessToken);

            OperationResult result = new OperationResult();

            if (accessTokens.Count == 0)
            {
                result.Result  = false;
                result.Data    = null;
                result.Message = "Access token does not exists. Please request for authorization by requesting to this url: " + ConfigurationManager.AppSettings["REQUEST.AUTHORIZATION.URL"];
            }
            else
            {
                AccessToken acctoken = accessTokens[0];
                if (acctoken.ExpiredDate > DateTime.Now)
                {
                    result = new OperationResult(true, accessTokens[0]);
                }
                else
                {
                    result.Result  = false;
                    result.Data    = null;
                    result.Message = "Access token has expired. Please request for new access token by requesting to this url: " + ConfigurationManager.AppSettings["REQUEST.REFRESHACCESSTOKEN.URL"];
                }
            }

            return(result);
        }
        /// <summary>
        /// Finds all  Access Token data with access Token String containing specified keyword
        /// </summary>
        /// <param name="accessTokenString"> Access Token String</param>
        /// <returns>The result of the operation</returns>
        public OperationResult FindByAccessTokenString(string accessTokenString)
        {
            IFindAccessTokenRepository repository = (IFindAccessTokenRepository)RepositoryFactory.Create(Keywords.FindAccessToken);

            try
            {
                List <AccessToken> res = repository.FindByAccessTokenString(accessTokenString);
                return(new OperationResult(true, res));
            }
            catch (Exception e)
            {
                return(new OperationResult(false, e));
            }
        }