AppFabric Caching Extension

using System;
using System.Collections.Generic;
using System.ServiceModel;
using System.Threading;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;
using TracingLibrary;
using CachingExtension;
using System.Collections.Specialized;

namespace WCFService
{
    public class WCFService : IWCFService
    {
        private const string CATEGORY_KEY_FORMAT = "Category-{0}";
        private const string CATEGORY_LIST_KEY = "CategoryList";

        List<CustomerDC> customers = new List<CustomerDC>();
        
        private string strConnection = ConfigurationManager.ConnectionStrings["strConnection"].ToString();
        private static CacheHelper _helper;              

        public List<CustomerDC> GetAllCustomers(string cust)
        {
            try
            {
                return GetCustomerFromDB();
            }
            catch(FaultException ex)
            {
                throw new FaultException(ex.Message);
            }
        }

        public CustomerDC GetCustomer(string customerID)
        {
            TraceEvents.AddEvent("Inside GetCustomer");
            for (int i = 0; i < 5; i++)
            {
                Console.WriteLine("Sleep for 2 seconds.");
                Thread.Sleep(2000);
            }
            return new CustomerDC()
            {
                CustomerID = "TRST",
                FirstName = "Steve",
                LastName = "Jobs",
                CompanyName = "Apple"
            };
        }

        public string ExampleManualCacheUse()
        {
            string retStr = "inside business  layer";
            
            //Do this in constructor
            _helper = new CacheHelper();

            string key = _helper.GetEncryptedKey(CATEGORY_LIST_KEY);

            //Cache-aside pattern
            object obj = _helper.GetFromCache(key);
            if (obj == null)
            {
                //get obj from datastore
                _helper.PutInCache(key, retStr, new TimeSpan(0, 1, 0));                
                TraceEvents.AddEvent("value returned from program");
            }
            else
            {
                TraceEvents.AddEvent("value returned from cache");
            }
            return retStr;
        }

        public IEnumerable<string> GetEvents()
        {
            return TraceEvents.Events;
        }

        public void RemoveEvents()
        {
           TraceEvents.RemoveEvents();
        }

        public List<CustomerDC> GetCustomerFromDB()
        {
            TraceEvents.AddEvent("Inside GetCustomerFromDB method");

            SqlConnection objConnection = new SqlConnection(strConnection);
            SqlCommand selectCMD = new SqlCommand("SELECT CustomerID, FirstName, LastName, CompanyName  FROM SalesLT.Customer", objConnection);
            selectCMD.CommandTimeout = 30;

            SqlDataAdapter CustomerDA = new SqlDataAdapter();
            CustomerDA.SelectCommand = selectCMD;

            objConnection.Open();

            DataSet CustomerDS = new DataSet();
            CustomerDA.Fill(CustomerDS, "SalesLT.Customer");

            foreach (DataRow pRow in CustomerDS.Tables["SalesLT.Customer"].Rows)
            {
                CustomerDC customerDC = new CustomerDC();
                customerDC.CustomerID = pRow["CustomerID"].ToString();
                customerDC.FirstName = pRow["FirstName"].ToString();
                customerDC.LastName = pRow["LastName"].ToString();
                customerDC.CompanyName = pRow["CompanyName"].ToString();
                 
                customers.Add(customerDC);
            }
            return customers;

        }      

    }
}