URL重写之实现IHttpHandler接口 .net 2.0实现 (幻想曲作品)

using System;
using System.IO;
using System.Data;
using System.Configuration;
using System.Collections.Generic;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text;
using System.Text.RegularExpressions;
using Microsoft.VisualBasic;
//RegexInfo结构,用来存储从xml文件中读取到的数据 
public struct RegexInfo
{
public string _before;
public string _after;
public RegexInfo(string before, string after)
{
_before = before.ToLower();
_after = after.ToLower();
}
}
//ipFilter结构,用来存储被封的IP 
public struct ipFilter
{
public string _ip;
public ipFilter(string ip)
{
_ip = ip;
}
}
public class HtmlHttpHandler : IHttpHandler   //实现IHttpHandler接口 
{
private List<RegexInfo> _regex_list = new List<RegexInfo>();
private List<ipFilter> _ip_filter = new List<ipFilter>();
public HtmlHttpHandler()
{
DataSet ds = new DataSet();
//读取url重写规则文件,并写入RegexInfo结构的实例中 
        ds.ReadXml(System.Web.HttpContext.Current.Server.MapPath("~/App_Data/Regexs.xml"));
foreach (DataRow r in ds.Tables["regex"].Rows)
_regex_list.Add(new RegexInfo(((string) r["b"]).Trim(), ((string) r["a"]).Trim()));
ds.Reset();
//读取被封的IP列表 
        ds.ReadXml(System.Web.HttpContext.Current.Server.MapPath("~/App_Data/ipFilter.xml"));
foreach (DataRow r in ds.Tables["IpFilters"].Rows)
_ip_filter.Add(new ipFilter((string) r["ip"]));
}
public void ProcessRequest(HttpContext context)
{
string _ip = context.Request.UserHostAddress;   //获取IP 
        foreach (ipFilter r in _ip_filter)
{
if (_ip == r._ip)
{
context.Response.Write("对不起,您的IP:" + _ip + "已被限制!");
context.Response.End();
}
}
string path = context.Request.Path.ToLower();   //获取当前访问的重写过的虚假URL 
        foreach (RegexInfo r in _regex_list)
path = Regex.Replace(path, r._before, r._after);      //匹配出其真实的URL 
        context.Server.Execute(path);
}
// Override the IsReusable property. 
    public bool IsReusable
{
get { return true; }
}
}