using System;using System.IO;using System.Threading;using System.Web;using Com.Website.Configuration;using Com.Website.WebModel.Resource;using Com.Website.DomainModel;namespace Com.Website.HttpModule.UrlRewriter{    /// 
    /// Url rewrite http module    /// 
    public class UrlRewriteHttpModule : IHttpModule    {        private UrlHelper urlHelper;        private RewriteRuleCollection rewriteRuleList = new RewriteRuleCollection();        public UrlRewriteHttpModule()        {            this.urlHelper = new UrlHelper();        }        #region IHttpModule Members        public void Init(HttpApplication context)        {            context.BeginRequest += new EventHandler(OnBeginRequest);        }        public void Dispose()        {        }        #endregion        private void InitialSetting()        {            rewriteRuleList.Clear();            foreach (RewriteSetting rewriteSetting in ConfigurationManager.UrlRewriterConfiguration.RewriteConfiguration.RewriteSettingCollection)            {                RewriteRule rewrite = null;                string providerName = rewriteSetting.Provider;                if (string.IsNullOrEmpty(providerName))                {                    rewrite = UrlRewrite.CreateRewriteRule();                }                else                {                    rewrite = UrlRewrite.CreateRewriteRule(providerName);                }                rewrite.Initialize(rewriteSetting);                rewriteRuleList.Add(rewrite);            }        }        private void OnBeginRequest(object sender, EventArgs e)        {            HttpApplication application = sender as HttpApplication;            if (File.Exists(application.Request.PhysicalPath)) return;            if (!(ConfigurationManager.BizConfiguration != null                     && ConfigurationManager.UrlRewriterConfiguration != null                    && ConfigurationManager.UrlRewriterConfiguration.RewriteConfiguration != null                    && ConfigurationManager.UrlRewriterConfiguration.RewriteConfiguration.RewriteSettingCollection != null))                return;            string pageName = string.Empty;            if (HttpContext.Current != null &&                 HttpContext.Current.Request != null &&                HttpContext.Current.Request.Url != null)            {                pageName = HttpContext.Current.Request.Url.AbsolutePath;            }            PageUrlAlias currentAlias = PageUrlAlias.InvalidUrl;            if (!string.IsNullOrWhiteSpace(pageName))            {                currentAlias = ConfigurationManager.WebPageConfiguration.GetPageUrlAlias(pageName);            }            if (ConfigurationManager.UrlRewriterConfiguration.ExceptPage != null                && ConfigurationManager.UrlRewriterConfiguration.ExceptPage.Pages != null                && ConfigurationManager.UrlRewriterConfiguration.ExceptPage.Pages.Exists(d => d == currentAlias))            {                return;            }            InitialSetting();            string requestUrl = application.Request.RawUrl;            string requestQuerystring = string.Empty;            string virtualUrl = requestUrl;            int pos = requestUrl.IndexOf('?');            if (pos >= 0)            {                requestQuerystring = requestUrl.Substring(pos + 1);                virtualUrl = requestUrl.Substring(0, pos);            }            virtualUrl = virtualUrl.TrimEnd('/');            RewriteRule rewriteRule = rewriteRuleList.Find(new Predicate
     
      (delegate(RewriteRule rule) { return rule.IsRewrite(virtualUrl); }));            if (rewriteRule == null) return;            string destinationUrl = rewriteRule.RewriteUrl(virtualUrl);            destinationUrl = urlHelper.JoinUrlParameter(urlHelper.HandleRootOperator(destinationUrl), requestQuerystring);            HttpContext.Current.RewritePath(destinationUrl);        }    }}