private IDictionary<string, Order> _cache;

        private string _connectionString;

​

        public ctor(IDictionary<string, Order> cache, string connectionString)

        {

            _cache = cache;

            _connectionString = connectionString;

        }

​

        [WebMethod]

        public Order LoadOrderInfo(string orderCode)

        {

            try

            {

                Stopwatch stopWatch = new Stopwatch();

                stopWatch.Start();

​

                if (string.IsNullOrEmpty(orderCode))

                    throw new ArgumentException("OrderCode doen not provided.");

                lock (_cache)

                {

                    if (_cache.ContainsKey(orderCode))

                    {

                        stopWatch.Stop();

                        logger.Log("INFO",

                          "Elapsed - {0}", stopWatch.Elapsed);

                        return _cache[orderCode];

                    }

                }

​

                string queryTemplate =

                  "SELECT OrderID, CustomerID, TotalMoney" +

                  "  FROM dbo.Orders where OrderCode='{0}'";

                string query = string.Format(queryTemplate, orderCode);

​

                using (SqlConnection connection = new SqlConnection(_connectionString))

                using (SqlCommand command = new SqlCommand(query, connection))

                {

                    connection.Open();

                    SqlDataReader reader = command.ExecuteReader();

                    if (reader.Read())

                    {

                        Order order = new Order(

                          (string)reader[0],

                          (string)reader[1],

                          (int)reader[2]);

                        lock (_cache)

                        {

                            if (!_cache.ContainsKey(orderCode))

                                _cache[orderCode] = order;

                        }

                        stopWatch.Stop();

                        logger.Log("INFO", "Elapsed - {0}", stopWatch.Elapsed);

                        return order;

                    }

                }

                stopWatch.Stop();

                logger.Log("INFO", "Elapsed - {0}", stopWatch.Elapsed);

                return null;

            }

            catch (SqlException ex)

            {

                logger.Log("ERROR", ex.Message);

                throw new ApplicationException("Error");

            }

        }