CATCH缓存

using System;
using System.Collections.Generic;
using System.Data;
using System.Text;
using System.Web.Caching;

namespace IWOMWebCrawlerApp
{
    class CacheCenter
    {
        /// <summary>
        /// 通过缓存获取黑名单，这里有个问题即缓存无法更新
        /// </summary>
        public static DataTable GetSiteBlock()
        {
            string key = "siteblock";

            if (System.Web.HttpRuntime.Cache[key] != null)
                return (DataTable)System.Web.HttpRuntime.Cache[key];
            else
            {
                DataTable dtSiteBlock = IWOMWebCrawlerDbLayer.DAL.IwomCrawlerDAL.GetSiteBlock();
                System.Web.HttpRuntime.Cache.Insert(key, dtSiteBlock, null, DateTime.Now.AddMinutes(30), TimeSpan.Zero);
                return dtSiteBlock;
            }
        }
        /// <summary>
        /// 通过缓存获取过滤词和过滤url，这里有个问题即缓存无法更新
        /// </summary>
        public static DataTable GetBrandBlock(int BrandID)
        {
            string key = "brandblock" + BrandID;

            if (System.Web.HttpRuntime.Cache[key] != null)
                return (DataTable)System.Web.HttpRuntime.Cache[key];
            else
            {
                DataTable dtBrandBlock = IWOMWebCrawlerDbLayer.DAL.IwomCrawlerDAL.GetBrandBlock(BrandID);
                System.Web.HttpRuntime.Cache.Insert(key, dtBrandBlock, null, DateTime.Now.AddMinutes(30), TimeSpan.Zero);
                return dtBrandBlock;
            }
        }
    }
}