抓取csdn的数据

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代码质量不行，后面采集起来卡，原因是正则我太菜了，没有开多线程采集。下面我举例：

目标页面是http://bbs.csdn.net/recommend_tech_topics，有图有真相：

看看采集后的效果：

下面是采集到的每个帖子楼主的内容以及一些简单的显示。图片之所以没有显示出来，因为csdn是用的一个专门的图片服务器，设置了防盗链，这个自己捣鼓下应该也可以绕过去。

下面我来分析下：

抓取的原理：先获取对应url页面的html内容，然后根据找出你要抓取的目标数据的的html结构，看看这个结构是否有某种规律，然后用正则去匹配这个规则，匹配到了以后就可以扣出来。

先看看http://bbs.csdn.net/recommend_tech_topics这个页面的源代码：

再通过谷歌浏览器我们再次确认了，目标数据是位于<div class="list_1">...</div>中间的

可是怎么匹配呢，我百度了下，就是找某两个字符中间的内容。考虑到结尾</div>很多，我这里就偷懒，把<div class="list_1">...</div>这一对div和近邻着的的后面的一个div【从源代码上我们可以看到是：<div class="page_nav">】<div class="page_nav">放到一起来，所以我的正则出来了：

Regex regex = new Regex("<div class=\"list_1\">([\\s\\S]*)</div>([\\s\\S]*)<div class=\"page_nav\">",RegexOptions.Compiled);

为了美化一下，我加了点css，具体代码如下;

页面：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="testcollection.aspx.cs" Inherits="testcollection" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>测试获取网页信息</title>
    <script src="js/jquery-1.6.min.js" type="text/javascript"></script>
    <style type="text/css">
        a:link,a:visited {color: #335AA4;text-decoration: none;}
        a:hover,a:active {color: #CA0000;text-decoration: underline;}
        a.a_insertdb{ color:#f00; font-weight:bold;}
        a.a_insertdb:hover{ text-decoration:none;}
        
        #pageUrlInfo{ font-family:Arial,宋体; width:960px; margin:0 auto; font-size:14px;} 
        #pageUrlInfo ul,li{ list-style:none;}
        #pageUrlInfo ul li{ line-height:23px;}
        .list_1 .time {float: right;color: #999;font-size: 12px;}
        
        .pageBar{width:960px; margin:0 auto; font-size:14px;}
        .pageBar ul li{ float:right; width:100px;}
    </style>
</head>
<body name="top">
    <%--<a name="top"></a>--%>
    <div class="pageBar">
        <ul>
            <li><a href="#bottom">回到底部</a></li>
            <li><a href="testcollection.aspx?page=<%=(int.Parse(pageindex)+1).ToString() %>">下一页</a></li>
            <li><a href="testcollection.aspx?page=<%=(int.Parse(pageindex)-(pageindex!="1" ? 1 : 0 )).ToString() %>">上一页</a></li>            
            <li><a href="javascript:void(null);" class="a_insertdb">导入数据库</a></li>
        </ul>
    </div><br />
    <form id="form1" runat="server">
    <div runat="server" id="pageUrlInfo">
        
    </div>
    <a name="bottom"></a>
    <div class="pageBar" style=" width:960px; margin:0 auto;">
        <ul>
            <li><a href="#top">回到顶部</a></li>
            <li><a href="testcollection.aspx?page=<%=(int.Parse(pageindex)+1).ToString() %>">下一页</a></li>
            <li><a href="testcollection.aspx?page=<%=(int.Parse(pageindex)-(pageindex!="1" ? 1 : 0 )).ToString() %>">上一页</a></li>            
        </ul>
    </div>
    </form>
    <script type="text/javascript">
        $(document).ready(function() {
            $(".list_1 ul li a").each(function() {
                var _urlSuffix = $(this).attr("href");
                $(this).attr({ "href": "<%=HttpUrlDomain %>" + _urlSuffix,"target": "_blank" });
            })
            $(".a_insertdb").click(function() {
                var _json = GetSelectedCustomer();
                //alert(_json); return;
                $.ajax({
                    type: "POST",url: "ajax/news_gather.aspx",data: "pjson=" + _json + "&pt=" + (new Date().getTime()),success: function(msg) {
                        alert("Data Saved: " + msg);
                    }
                });

            })
        })

        function GetSelectedCustomer() {
            var item = $(".list_1 ul li").map(function() {
                var _title = $(this).find("a");
                var _time = $(this).find("span").text();
                return '{' + _title.text() + '$$' + _title.attr("href") + '$$' + $(this).text().replace(_title.text(),"").replace(_time,"").match(/[0-9]+/) + '$$' + _time + '}';
            }).get().join(",");
            return '[' + item + ']';
        }
    </script>
</body>
</html>

后台文件：

using System;
using System.IO;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;

public partial class testcollection : System.Web.UI.Page
{
    protected void Page_Load(object sender,EventArgs e)
    {
        ///recommend_tech_topics?page=2
        string rl;
        WebRequest myReq = WebRequest.Create(HttpUrlDomain + "/recommend_tech_topics?page=" + pageindex);
        WebResponse myRes = myReq.GetResponse();
        Stream resStream = myRes.GetResponseStream();
        StreamReader sr = new StreamReader(resStream,Encoding.UTF8);
        StringBuilder sb = new StringBuilder();
        while ((rl = sr.ReadLine()) != null)
        {
            sb.AppendLine(rl);
        }

        Regex regex = new Regex("<div class=\"list_1\">([\\s\\S]*)</div>([\\s\\S]*)<div class=\"page_nav\">",RegexOptions.Compiled);
        Match match;
        match = regex.Match(sb.ToString());
        if (match.Success)
            this.pageUrlInfo.InnerHtml = match.Groups[0].Value;

        myRes.Close();
    }
    /// <summary>
    /// 获取页码
    /// </summary>
    public string pageindex
    {
        get
        {
            return Request.QueryString["page"] != null ?
                (int.Parse(Request.QueryString["page"].ToString()) > 0 ? Request.QueryString["page"].ToString() : "1")
                : "1";
        }
    }
    public string HttpUrlDomain
    {
        get { return "http://bbs.csdn.net"; }
    }   
}

最终效果：

news_gather.aspx：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="news_gather.aspx.cs" Inherits="ajax_news_gather" %>

news_gather.aspx.cs:

using System;
using System.IO;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Web;
//using System.Threading;

public partial class ajax_news_gather : System.Web.UI.Page
{
    public Test_Model.CSDN_BBS csdnModel = new Test_Model.CSDN_BBS();
    public Test_BUL.CSDN_BBS csdnDal = new Test_BUL.CSDN_BBS();
    protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);

        if (!CheckFormUrl())
            Response.End();
    }
    public bool CheckFormUrl()
    {
        if (HttpContext.Current.Request.UrlReferrer == null)
            return false;
        if ((HttpContext.Current.Request.UrlReferrer.Host) != (HttpContext.Current.Request.Url.Host))
            return false;

        return true;
    }

    protected void Page_Load(object sender,EventArgs e)
    {
        string jsondata = Request.Form["pjson"] != null ? Request.Form["pjson"].ToString() : "";
        Regex reg1 = new Regex(@"{.+?}");
        MatchCollection mc = reg1.Matches(jsondata);
        string[] itmeArry;
        for (int i = 0; i < mc.Count; i++)
        {
            itmeArry = mc[i].Value.Replace("{","").Replace("}","").Split(new string[] { "$$" },StringSplitOptions.RemoveEmptyEntries);

            csdnModel.Title = itmeArry[0];
            csdnModel.Content = GetContent(itmeArry[1]);
            csdnModel.Href = itmeArry[1];
            csdnModel.Date = Convert.ToDateTime(itmeArry[3]);
            csdnModel.ClickNum = int.Parse(itmeArry[2].Trim());
            csdnDal.Add(csdnModel);
        }

        Response.Write("OK");
    }

    //private void GetUrlInfo()
    //{
    //    Thread[] downloadThread = new Thread[5];//为线程申请资源，确定线程总数
    //    for (int i = 0; i < downloadThread.Length; i++)
    //    {
    //        downloadThread[i] = new Thread(new ThreadStart(DownLoad));//创建一个线程
    //        downloadThread[i].Start();//逐个开启线程
    //    }
    //}

    //private void DownLoad()
    //{
    //    //执行一些方法
    //}

    private string GetContent(string url)
    {
        string rl;
        WebRequest myReq = WebRequest.Create(url);
        WebResponse myRes = myReq.GetResponse();
        Stream resStream = myRes.GetResponseStream();
        StreamReader sr = new StreamReader(resStream,Encoding.UTF8);
        StringBuilder sb = new StringBuilder();
        while ((rl = sr.ReadLine()) != null)
        {
            sb.AppendLine(rl);
        }

        try
        {
            string pattStr = "<div class=\"data\">([\\s\\S]*)<strong class=\"fr\">([\\s\\S]*)楼主([\\s\\S]*)<div class=\"post_body\">([\\s\\S]*)<iframe id=\"tad2\"";
            Regex regex = new Regex(pattStr,RegexOptions.Compiled);
            Match match;
            match = regex.Match(sb.ToString());
            if (match.Success)
                return match.Groups[0].Value.Replace("<iframe id=\"tad2\"","").Replace("楼主","");
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
        finally
        {
            myRes.Close();
        }
        return null;
    }
}

model:

using System;

namespace Test_Model
{
    /// <summary>
    /// CSDN_BBS:实体类
    /// </summary>
    [Serializable]
    public partial class CSDN_BBS : IDisposable
    {
        #region 接口实现
        /// <summary>
        /// 终结器,调用虚拟的Dispose方法
        /// </summary>
        ~CSDN_BBS()
        {
            Dispose(false);
        }

        /// <summary>
        /// 调用虚拟的Dispose方法,禁止Finalization（终结操作）
        /// </summary>
        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        /// <summary>
        /// 虚拟的Dispose方法
        /// </summary>
        protected virtual void Dispose(bool disposing)
        {
            if (!disposing)
                return;
        }
        #endregion

        public CSDN_BBS()
        { }

        #region Model
        private int _id;
        private string _title;
        private string _href;
        private string _content;
        private DateTime? _date;
        private int _clicknum;

        /// <summary>
        /// 
        /// </summary>
        public int ID
        {
            set { _id = value; }
            get { return _id; }
        }
        /// <summary>
        /// 
        /// </summary>
        public string Title
        {
            set { _title = value; }
            get { return _title; }
        }
        /// <summary>
        /// 
        /// </summary>
        public string Href
        {
            set { _href = value; }
            get { return _href; }
        }
        /// <summary>
        /// 
        /// </summary>
        public string Content
        {
            set { _content = value; }
            get { return _content; }
        }
        /// <summary>
        /// 
        /// </summary>
        public DateTime? Date
        {
            set { _date = value; }
            get { return _date; }
        }
        /// <summary>
        /// 
        /// </summary>
        public int ClickNum
        {
            set { _clicknum = value; }
            get { return _clicknum; }
        }
        #endregion Model
    }
}

其它的我就不写了，获取每个标题的楼主发的内容和获取数据的思路一样，真心话我正则不会，都是依葫芦画瓢取目标字符串中间的内容。所以获取楼主的内容我也只能套了好几层，那个地方的div是循环出来的，结构包括css都是一个样子，我只能根据微末的变化来这么处理了。各位看官凑合着看吧原文链接：https://www.f2er.com/regex/362996.html

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