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[ASP.net教程]网络爬虫+HtmlAgilityPack+windows服务从博客园爬取20万博文


1.前言

最新在公司做一个项目,需要一些文章类的数据,当时就想到了用网络爬虫去一些技术性的网站爬一些,当然我经常去的就是博客园,于是就有下面的这篇文章。

2.准备工作

我需要把我从博客园爬取的数据,保存起来,最好的方式当然是保存到数据库中去了,好了我们先建一个数据库,在来一张表,保存我们的数据,其实都很简单的了啊,如下图所示

BlogArticleId博文自增ID,BlogTitle博文标题,BlogUrl博文地址,BlogAuthor博文作者,BlogTime博文发布时间,BlogMotto作者座右铭,BlogDepth蜘蛛爬虫爬取的深度,IsDeleted是否删除。

数据库表也创建好了,我们先来一个数据库的帮助类。

  /// <summary>  /// 数据库帮助类  /// </summary>  public class MssqlHelper  {    #region 字段属性    /// <summary>    /// 数据库连接字符串    /// </summary>    private static string conn = "Data Source=.;Initial Catalog=Cnblogs;User ID=sa;Password=123";    #endregion    #region DataTable写入数据    public static void GetData(string title, string url, string author, string time, string motto, string depth, DataTable dt)    {      DataRow dr;      dr = dt.NewRow();      dr["BlogTitle"] = title;      dr["BlogUrl"] = url;      dr["BlogAuthor"] = author;      dr["BlogTime"] = time;      dr["BlogMotto"] = motto;      dr["BlogDepth"] = depth;      //2.0 将dr追加到dt中      dt.Rows.Add(dr);    }    #endregion    #region 插入数据到数据库    /// <summary>    /// 插入数据到数据库    /// </summary>    public static void InsertDb(DataTable dt)    {      try      {        using (System.Data.SqlClient.SqlBulkCopy copy = new System.Data.SqlClient.SqlBulkCopy(conn))        {          //3.0.1 指定数据插入目标表名称          copy.DestinationTableName = "BlogArticle";          //3.0.2 告诉SqlBulkCopy对象 内存表中的 OrderNO1和Userid1插入到OrderInfos表中的哪些列中          copy.ColumnMappings.Add("BlogTitle", "BlogTitle");          copy.ColumnMappings.Add("BlogUrl", "BlogUrl");          copy.ColumnMappings.Add("BlogAuthor", "BlogAuthor");          copy.ColumnMappings.Add("BlogTime", "BlogTime");          copy.ColumnMappings.Add("BlogMotto", "BlogMotto");          copy.ColumnMappings.Add("BlogDepth", "BlogDepth");          //3.0.3 将内存表dt中的数据一次性批量插入到OrderInfos表中          copy.WriteToServer(dt);          dt.Rows.Clear();        }      }      catch (Exception)      {        dt.Rows.Clear();      }    }    #endregion  }

3.日志

来个日志,方便我们查看,代码如下。

  /// <summary>  /// 日志帮助类  /// </summary>  public class LogHelper  {    #region 写入日志    //写入日志    public static void WriteLog(string text)    {      //StreamWriter sw = new StreamWriter(AppDomain.CurrentDomain.BaseDirectory + "\\log.txt", true);      StreamWriter sw = new StreamWriter("F:" + "\\log.txt", true);      sw.WriteLine(text);      sw.Close();//写入    }    #endregion  }

4.爬虫

我的网络蜘蛛爬虫,用的一个第三方类库,代码如下。

namespace Feng.SimpleCrawler{  using System;  /// <summary>  /// The add url event handler.  /// </summary>  /// <param name="args">  /// The args.  /// </param>  /// <returns>  /// The <see cref="bool"/>.  /// </returns>  public delegate bool AddUrlEventHandler(AddUrlEventArgs args);  /// <summary>  /// The add url event args.  /// </summary>  public class AddUrlEventArgs : EventArgs  {    #region Public Properties    /// <summary>    /// Gets or sets the depth.    /// </summary>    public int Depth { get; set; }    /// <summary>    /// Gets or sets the title.    /// </summary>    public string Title { get; set; }    /// <summary>    /// Gets or sets the url.    /// </summary>    public string Url { get; set; }    #endregion  }}

AddUrlEventArgs.cs
namespace Feng.SimpleCrawler{  using System;  using System.Collections;  /// <summary>  /// The bloom filter.  /// </summary>  /// <typeparam name="T">  /// The generic type.  /// </typeparam>  public class BloomFilter<T>  {    #region Fields    /// <summary>    /// The get hash secondary.    /// </summary>    private readonly HashFunction getHashSecondary;    /// <summary>    /// The hash bits.    /// </summary>    private readonly BitArray hashBits;    /// <summary>    /// The hash function count.    /// </summary>    private readonly int hashFunctionCount;    #endregion    #region Constructors and Destructors    /// <summary>    /// Initializes a new instance of the <see cref="BloomFilter{T}"/> class.    /// </summary>    /// <param name="capacity">    /// The capacity.    /// </param>    public BloomFilter(int capacity)      : this(capacity, null)    {    }    /// <summary>    /// Initializes a new instance of the <see cref="BloomFilter{T}"/> class.    /// </summary>    /// <param name="capacity">    /// The capacity.    /// </param>    /// <param name="errorRate">    /// The error rate.    /// </param>    public BloomFilter(int capacity, int errorRate)      : this(capacity, errorRate, null)    {    }    /// <summary>    /// Initializes a new instance of the <see cref="BloomFilter{T}"/> class.    /// </summary>    /// <param name="capacity">    /// The capacity.    /// </param>    /// <param name="hashFunction">    /// The hash function.    /// </param>    public BloomFilter(int capacity, HashFunction hashFunction)      : this(capacity, BestErrorRate(capacity), hashFunction)    {    }    /// <summary>    /// Initializes a new instance of the <see cref="BloomFilter{T}"/> class.    /// </summary>    /// <param name="capacity">    /// The capacity.    /// </param>    /// <param name="errorRate">    /// The error rate.    /// </param>    /// <param name="hashFunction">    /// The hash function.    /// </param>    public BloomFilter(int capacity, float errorRate, HashFunction hashFunction)      : this(capacity, errorRate, hashFunction, BestM(capacity, errorRate), BestK(capacity, errorRate))    {    }    /// <summary>    /// Initializes a new instance of the <see cref="BloomFilter{T}"/> class.    /// </summary>    /// <param name="capacity">    /// The capacity.    /// </param>    /// <param name="errorRate">    /// The error rate.    /// </param>    /// <param name="hashFunction">    /// The hash function.    /// </param>    /// <param name="m">    /// The m.    /// </param>    /// <param name="k">    /// The k.    /// </param>    public BloomFilter(int capacity, float errorRate, HashFunction hashFunction, int m, int k)    {      if (capacity < 1)      {        throw new ArgumentOutOfRangeException("capacity", capacity, "capacity must be > 0");      }      if (errorRate >= 1 || errorRate <= 0)      {        throw new ArgumentOutOfRangeException(          "errorRate",           errorRate,           string.Format("errorRate must be between 0 and 1, exclusive. Was {0}", errorRate));      }      if (m < 1)      {        throw new ArgumentOutOfRangeException(          string.Format(            "The provided capacity and errorRate values would result in an array of length > int.MaxValue. Please reduce either of these values. Capacity: {0}, Error rate: {1}",             capacity,             errorRate));      }      if (hashFunction == null)      {        if (typeof(T) == typeof(string))        {          this.getHashSecondary = HashString;        }        else if (typeof(T) == typeof(int))        {          this.getHashSecondary = HashInt32;        }        else        {          throw new ArgumentNullException(            "hashFunction",             "Please provide a hash function for your type T, when T is not a string or int.");        }      }      else      {        this.getHashSecondary = hashFunction;      }      this.hashFunctionCount = k;      this.hashBits = new BitArray(m);    }    #endregion    #region Delegates    /// <summary>    /// The hash function.    /// </summary>    /// <param name="input">    /// The input.    /// </param>    /// <returns>    /// The <see cref="int"/>.    /// </returns>    public delegate int HashFunction(T input);    #endregion    #region Public Properties    /// <summary>    /// Gets the truthiness.    /// </summary>    public double Truthiness    {      get      {        return (double)this.TrueBits() / this.hashBits.Count;      }    }    #endregion    #region Public Methods and Operators    /// <summary>    /// The add.    /// </summary>    /// <param name="item">    /// The item.    /// </param>    public void Add(T item)    {      int primaryHash = item.GetHashCode();      int secondaryHash = this.getHashSecondary(item);      for (int i = 0; i < this.hashFunctionCount; i++)      {        int hash = this.ComputeHash(primaryHash, secondaryHash, i);        this.hashBits[hash] = true;      }    }    /// <summary>    /// The contains.    /// </summary>    /// <param name="item">    /// The item.    /// </param>    /// <returns>    /// The <see cref="bool"/>.    /// </returns>    public bool Contains(T item)    {      int primaryHash = item.GetHashCode();      int secondaryHash = this.getHashSecondary(item);      for (int i = 0; i < this.hashFunctionCount; i++)      {        int hash = this.ComputeHash(primaryHash, secondaryHash, i);        if (this.hashBits[hash] == false)        {          return false;        }      }      return true;    }    #endregion    #region Methods    /// <summary>    /// The best error rate.    /// </summary>    /// <param name="capacity">    /// The capacity.    /// </param>    /// <returns>    /// The <see cref="float"/>.    /// </returns>    private static float BestErrorRate(int capacity)    {      var c = (float)(1.0 / capacity);      if (Math.Abs(c) > 0)      {        return c;      }      double y = int.MaxValue / (double)capacity;      return (float)Math.Pow(0.6185, y);    }    /// <summary>    /// The best k.    /// </summary>    /// <param name="capacity">    /// The capacity.    /// </param>    /// <param name="errorRate">    /// The error rate.    /// </param>    /// <returns>    /// The <see cref="int"/>.    /// </returns>    private static int BestK(int capacity, float errorRate)    {      return (int)Math.Round(Math.Log(2.0) * BestM(capacity, errorRate) / capacity);    }    /// <summary>    /// The best m.    /// </summary>    /// <param name="capacity">    /// The capacity.    /// </param>    /// <param name="errorRate">    /// The error rate.    /// </param>    /// <returns>    /// The <see cref="int"/>.    /// </returns>    private static int BestM(int capacity, float errorRate)    {      return (int)Math.Ceiling(capacity * Math.Log(errorRate, 1.0 / Math.Pow(2, Math.Log(2.0))));    }    /// <summary>    /// The hash int 32.    /// </summary>    /// <param name="input">    /// The input.    /// </param>    /// <returns>    /// The <see cref="int"/>.    /// </returns>    private static int HashInt32(T input)    {      var x = input as uint?;      unchecked      {        x = ~x + (x << 15);        x = x ^ (x >> 12);        x = x + (x << 2);        x = x ^ (x >> 4);        x = x * 2057;        x = x ^ (x >> 16);        return (int)x;      }    }    /// <summary>    /// The hash string.    /// </summary>    /// <param name="input">    /// The input.    /// </param>    /// <returns>    /// The <see cref="int"/>.    /// </returns>    private static int HashString(T input)    {      var str = input as string;      int hash = 0;      if (str != null)      {        for (int i = 0; i < str.Length; i++)        {          hash += str[i];          hash += hash << 10;          hash ^= hash >> 6;        }        hash += hash << 3;        hash ^= hash >> 11;        hash += hash << 15;      }      return hash;    }    /// <summary>    /// The compute hash.    /// </summary>    /// <param name="primaryHash">    /// The primary hash.    /// </param>    /// <param name="secondaryHash">    /// The secondary hash.    /// </param>    /// <param name="i">    /// The i.    /// </param>    /// <returns>    /// The <see cref="int"/>.    /// </returns>    private int ComputeHash(int primaryHash, int secondaryHash, int i)    {      int resultingHash = (primaryHash + (i * secondaryHash)) % this.hashBits.Count;      return Math.Abs(resultingHash);    }    /// <summary>    /// The true bits.    /// </summary>    /// <returns>    /// The <see cref="int"/>.    /// </returns>    private int TrueBits()    {      int output = 0;      foreach (bool bit in this.hashBits)      {        if (bit)        {          output++;        }      }      return output;    }    #endregion  }}

BloomFilter.cs
namespace Feng.SimpleCrawler{  using System;  /// <summary>  /// The crawl error event handler.  /// </summary>  /// <param name="args">  /// The args.  /// </param>  public delegate void CrawlErrorEventHandler(CrawlErrorEventArgs args);  /// <summary>  /// The crawl error event args.  /// </summary>  public class CrawlErrorEventArgs : EventArgs  {    #region Public Properties    /// <summary>    /// Gets or sets the exception.    /// </summary>    public Exception Exception { get; set; }    /// <summary>    /// Gets or sets the url.    /// </summary>    public string Url { get; set; }    #endregion  }}

CrawlErrorEventArgs.cs
namespace Feng.SimpleCrawler{  using System;  /// <summary>  /// The crawl error event handler.  /// </summary>  /// <param name="args">  /// The args.  /// </param>  public delegate void CrawlErrorEventHandler(CrawlErrorEventArgs args);  /// <summary>  /// The crawl error event args.  /// </summary>  public class CrawlErrorEventArgs : EventArgs  {    #region Public Properties    /// <summary>    /// Gets or sets the exception.    /// </summary>    public Exception Exception { get; set; }    /// <summary>    /// Gets or sets the url.    /// </summary>    public string Url { get; set; }    #endregion  }}

CrawlExtension.cs
namespace Feng.SimpleCrawler{  using System;  using System.Collections.Generic;  using System.IO;  using System.IO.Compression;  using System.Linq;  using System.Net;  using System.Text;  using System.Text.RegularExpressions;  using System.Threading;    /// <summary>  /// The crawl master.  /// </summary>  public class CrawlMaster  {    #region Constants    /// <summary>    /// The web url regular expressions.    /// </summary>    private const string WebUrlRegularExpressions = @"^(http|https)://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?";    #endregion    #region Fields    /// <summary>    /// The cookie container.    /// </summary>    private readonly CookieContainer cookieContainer;    /// <summary>    /// The random.    /// </summary>    private readonly Random random;    /// <summary>    /// The thread status.    /// </summary>    private readonly bool[] threadStatus;    /// <summary>    /// The threads.    /// </summary>    private readonly Thread[] threads;    #endregion    #region Constructors and Destructors    /// <summary>    /// Initializes a new instance of the <see cref="CrawlMaster"/> class.    /// </summary>    /// <param name="settings">    /// The settings.    /// </param>    public CrawlMaster(CrawlSettings settings)    {      this.cookieContainer = new CookieContainer();      this.random = new Random();      this.Settings = settings;      this.threads = new Thread[settings.ThreadCount];      this.threadStatus = new bool[settings.ThreadCount];    }    #endregion    #region Public Events    /// <summary>    /// The add url event.    /// </summary>    public event AddUrlEventHandler AddUrlEvent;    /// <summary>    /// The crawl error event.    /// </summary>    public event CrawlErrorEventHandler CrawlErrorEvent;    /// <summary>    /// The data received event.    /// </summary>    public event DataReceivedEventHandler DataReceivedEvent;    #endregion    #region Public Properties    /// <summary>    /// Gets the settings.    /// </summary>    public CrawlSettings Settings { get; private set; }    #endregion    #region Public Methods and Operators    /// <summary>    /// The crawl.    /// </summary>    public void Crawl()    {      this.Initialize();      for (int i = 0; i < this.threads.Length; i++)      {        this.threads[i].Start(i);        this.threadStatus[i] = false;      }    }    /// <summary>    /// The stop.    /// </summary>    public void Stop()    {      foreach (Thread thread in this.threads)      {        thread.Abort();      }    }    #endregion    #region Methods    /// <summary>    /// The config request.    /// </summary>    /// <param name="request">    /// The request.    /// </param>    private void ConfigRequest(HttpWebRequest request)    {      request.UserAgent = this.Settings.UserAgent;      request.CookieContainer = this.cookieContainer;      request.AllowAutoRedirect = true;      request.MediaType = "text/html";      request.Headers["Accept-Language"] = "zh-CN,zh;q=0.8";      if (this.Settings.Timeout > 0)      {        request.Timeout = this.Settings.Timeout;      }    }    /// <summary>    /// The crawl process.    /// </summary>    /// <param name="threadIndex">    /// The thread index.    /// </param>    private void CrawlProcess(object threadIndex)    {      var currentThreadIndex = (int)threadIndex;      while (true)      {        // 根据队列中的 Url 数量和空闲线程的数量,判断线程是睡眠还是退出        if (UrlQueue.Instance.Count == 0)        {          this.threadStatus[currentThreadIndex] = true;          if (!this.threadStatus.Any(t => t == false))          {            break;          }          Thread.Sleep(2000);          continue;        }        this.threadStatus[currentThreadIndex] = false;        if (UrlQueue.Instance.Count == 0)        {          continue;        }        UrlInfo urlInfo = UrlQueue.Instance.DeQueue();        HttpWebRequest request = null;        HttpWebResponse response = null;        try        {          if (urlInfo == null)          {            continue;          }          // 1~5 秒随机间隔的自动限速          if (this.Settings.AutoSpeedLimit)          {            int span = this.random.Next(1000, 5000);            Thread.Sleep(span);          }          // 创建并配置Web请求          request = WebRequest.Create(urlInfo.UrlString) as HttpWebRequest;          this.ConfigRequest(request);          if (request != null)          {            response = request.GetResponse() as HttpWebResponse;          }          if (response != null)          {            this.PersistenceCookie(response);            Stream stream = null;            // 如果页面压缩,则解压数据流            if (response.ContentEncoding == "gzip")            {              Stream responseStream = response.GetResponseStream();              if (responseStream != null)              {                stream = new GZipStream(responseStream, CompressionMode.Decompress);              }            }            else            {              stream = response.GetResponseStream();            }            using (stream)            {              string html = this.ParseContent(stream, response.CharacterSet);              this.ParseLinks(urlInfo, html);              if (this.DataReceivedEvent != null)              {                this.DataReceivedEvent(                  new DataReceivedEventArgs                    {                      Url = urlInfo.UrlString,                       Depth = urlInfo.Depth,                       Html = html                    });              }              if (stream != null)              {                stream.Close();              }            }          }        }        catch (Exception exception)        {          if (this.CrawlErrorEvent != null)          {            if (urlInfo != null)            {              this.CrawlErrorEvent(                new CrawlErrorEventArgs { Url = urlInfo.UrlString, Exception = exception });            }          }        }        finally        {          if (request != null)          {            request.Abort();          }          if (response != null)          {            response.Close();          }        }      }    }    /// <summary>    /// The initialize.    /// </summary>    private void Initialize()    {      if (this.Settings.SeedsAddress != null && this.Settings.SeedsAddress.Count > 0)      {        foreach (string seed in this.Settings.SeedsAddress)        {          if (Regex.IsMatch(seed, WebUrlRegularExpressions, RegexOptions.IgnoreCase))          {            UrlQueue.Instance.EnQueue(new UrlInfo(seed) { Depth = 1 });          }        }      }      for (int i = 0; i < this.Settings.ThreadCount; i++)      {        var threadStart = new ParameterizedThreadStart(this.CrawlProcess);        this.threads[i] = new Thread(threadStart);      }      ServicePointManager.DefaultConnectionLimit = 256;    }    /// <summary>    /// The is match regular.    /// </summary>    /// <param name="url">    /// The url.    /// </param>    /// <returns>    /// The <see cref="bool"/>.    /// </returns>    private bool IsMatchRegular(string url)    {      bool result = false;      if (this.Settings.RegularFilterExpressions != null && this.Settings.RegularFilterExpressions.Count > 0)      {        if (          this.Settings.RegularFilterExpressions.Any(            pattern => Regex.IsMatch(url, pattern, RegexOptions.IgnoreCase)))        {          result = true;        }      }      else      {        result = true;      }      return result;    }    /// <summary>    /// The parse content.    /// </summary>    /// <param name="stream">    /// The stream.    /// </param>    /// <param name="characterSet">    /// The character set.    /// </param>    /// <returns>    /// The <see cref="string"/>.    /// </returns>    private string ParseContent(Stream stream, string characterSet)    {      var memoryStream = new MemoryStream();      stream.CopyTo(memoryStream);      byte[] buffer = memoryStream.ToArray();      Encoding encode = Encoding.ASCII;      string html = encode.GetString(buffer);      string localCharacterSet = characterSet;      Match match = Regex.Match(html, "<meta([^<]*)charset=([^<]*)\"", RegexOptions.IgnoreCase);      if (match.Success)      {        localCharacterSet = match.Groups[2].Value;        var stringBuilder = new StringBuilder();        foreach (char item in localCharacterSet)        {          if (item == ' ')          {            break;          }          if (item != '\"')          {            stringBuilder.Append(item);          }        }        localCharacterSet = stringBuilder.ToString();      }      if (string.IsNullOrEmpty(localCharacterSet))      {        localCharacterSet = characterSet;      }      if (!string.IsNullOrEmpty(localCharacterSet))      {        encode = Encoding.GetEncoding(localCharacterSet);      }      memoryStream.Close();      return encode.GetString(buffer);    }    /// <summary>    /// The parse links.    /// </summary>    /// <param name="urlInfo">    /// The url info.    /// </param>    /// <param name="html">    /// The html.    /// </param>    private void ParseLinks(UrlInfo urlInfo, string html)    {      if (this.Settings.Depth > 0 && urlInfo.Depth >= this.Settings.Depth)      {        return;      }      var urlDictionary = new Dictionary<string, string>();      Match match = Regex.Match(html, "(?i)<a .*?href=\"([^\"]+)\"[^>]*>(.*?)</a>");      while (match.Success)      {        // 以 href 作为 key        string urlKey = match.Groups[1].Value;        // 以 text 作为 value        string urlValue = Regex.Replace(match.Groups[2].Value, "(?i)<.*?>", string.Empty);        urlDictionary[urlKey] = urlValue;        match = match.NextMatch();      }      foreach (var item in urlDictionary)      {        string href = item.Key;        string text = item.Value;        if (!string.IsNullOrEmpty(href))        {          bool canBeAdd = true;          if (this.Settings.EscapeLinks != null && this.Settings.EscapeLinks.Count > 0)          {            if (this.Settings.EscapeLinks.Any(suffix => href.EndsWith(suffix, StringComparison.OrdinalIgnoreCase)))            {              canBeAdd = false;            }          }          if (this.Settings.HrefKeywords != null && this.Settings.HrefKeywords.Count > 0)          {            if (!this.Settings.HrefKeywords.Any(href.Contains))            {              canBeAdd = false;            }          }          if (canBeAdd)          {            string url = href.Replace("%3f", "?")              .Replace("%3d", "=")              .Replace("%2f", "/")              .Replace("&amp;", "&");            if (string.IsNullOrEmpty(url) || url.StartsWith("#")              || url.StartsWith("mailto:", StringComparison.OrdinalIgnoreCase)              || url.StartsWith("javascript:", StringComparison.OrdinalIgnoreCase))            {              continue;            }            var baseUri = new Uri(urlInfo.UrlString);            Uri currentUri = url.StartsWith("http", StringComparison.OrdinalIgnoreCase)                       ? new Uri(url)                       : new Uri(baseUri, url);            url = currentUri.AbsoluteUri;            if (this.Settings.LockHost)            {              // 去除二级域名后,判断域名是否相等,相等则认为是同一个站点              // 例如:mail.pzcast.com 和 www.pzcast.com              if (baseUri.Host.Split('.').Skip(1).Aggregate((a, b) => a + "." + b)                != currentUri.Host.Split('.').Skip(1).Aggregate((a, b) => a + "." + b))              {                continue;              }            }            if (!this.IsMatchRegular(url))            {              continue;            }            var addUrlEventArgs = new AddUrlEventArgs { Title = text, Depth = urlInfo.Depth + 1, Url = url };            if (this.AddUrlEvent != null && !this.AddUrlEvent(addUrlEventArgs))            {              continue;            }            UrlQueue.Instance.EnQueue(new UrlInfo(url) { Depth = urlInfo.Depth + 1 });          }        }      }    }    /// <summary>    /// The persistence cookie.    /// </summary>    /// <param name="response">    /// The response.    /// </param>    private void PersistenceCookie(HttpWebResponse response)    {      if (!this.Settings.KeepCookie)      {        return;      }      string cookies = response.Headers["Set-Cookie"];      if (!string.IsNullOrEmpty(cookies))      {        var cookieUri =          new Uri(            string.Format(              "{0}://{1}:{2}/",               response.ResponseUri.Scheme,               response.ResponseUri.Host,               response.ResponseUri.Port));        this.cookieContainer.SetCookies(cookieUri, cookies);      }    }    #endregion  }}

CrawlMaster.cs
namespace Feng.SimpleCrawler{  using System;  using System.Collections.Generic;  /// <summary>  /// The crawl settings.  /// </summary>  [Serializable]  public class CrawlSettings  {    #region Fields    /// <summary>    /// The depth.    /// </summary>    private byte depth = 3;    /// <summary>    /// The lock host.    /// </summary>    private bool lockHost = true;    /// <summary>    /// The thread count.    /// </summary>    private byte threadCount = 1;    /// <summary>    /// The timeout.    /// </summary>    private int timeout = 15000;    /// <summary>    /// The user agent.    /// </summary>    private string userAgent =       "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.97 Safari/537.11";    #endregion    #region Constructors and Destructors    /// <summary>    /// Initializes a new instance of the <see cref="CrawlSettings"/> class.    /// </summary>    public CrawlSettings()    {      this.AutoSpeedLimit = false;      this.EscapeLinks = new List<string>();      this.KeepCookie = true;      this.HrefKeywords = new List<string>();      this.LockHost = true;      this.RegularFilterExpressions = new List<string>();      this.SeedsAddress = new List<string>();    }    #endregion    #region Public Properties    /// <summary>    /// Gets or sets a value indicating whether auto speed limit.    /// </summary>    public bool AutoSpeedLimit { get; set; }    /// <summary>    /// Gets or sets the depth.    /// </summary>    public byte Depth    {      get      {        return this.depth;      }      set      {        this.depth = value;      }    }    /// <summary>    /// Gets the escape links.    /// </summary>    public List<string> EscapeLinks { get; private set; }    /// <summary>    /// Gets or sets a value indicating whether keep cookie.    /// </summary>    public bool KeepCookie { get; set; }    /// <summary>    /// Gets the href keywords.    /// </summary>    public List<string> HrefKeywords { get; private set; }    /// <summary>    /// Gets or sets a value indicating whether lock host.    /// </summary>    public bool LockHost    {      get      {        return this.lockHost;      }      set      {        this.lockHost = value;      }    }    /// <summary>    /// Gets the regular filter expressions.    /// </summary>    public List<string> RegularFilterExpressions { get; private set; }    /// <summary>    /// Gets the seeds address.    /// </summary>    public List<string> SeedsAddress { get; private set; }    /// <summary>    /// Gets or sets the thread count.    /// </summary>    public byte ThreadCount    {      get      {        return this.threadCount;      }      set      {        this.threadCount = value;      }    }    /// <summary>    /// Gets or sets the timeout.    /// </summary>    public int Timeout    {      get      {        return this.timeout;      }      set      {        this.timeout = value;      }    }    /// <summary>    /// Gets or sets the user agent.    /// </summary>    public string UserAgent    {      get      {        return this.userAgent;      }      set      {        this.userAgent = value;      }    }    #endregion  }}

CrawlSettings.cs
namespace Feng.SimpleCrawler{  /// <summary>  /// The crawl status.  /// </summary>  public enum CrawlStatus  {    /// <summary>    /// The completed.    /// </summary>    Completed = 1,     /// <summary>    /// The never been.    /// </summary>    NeverBeen = 2  }}

CrawlStatus.cs
namespace Feng.SimpleCrawler{  using System;  /// <summary>  /// The data received event handler.  /// </summary>  /// <param name="args">  /// The args.  /// </param>  public delegate void DataReceivedEventHandler(DataReceivedEventArgs args);  /// <summary>  /// The data received event args.  /// </summary>  public class DataReceivedEventArgs : EventArgs  {    #region Public Properties    /// <summary>    /// Gets or sets the depth.    /// </summary>    public int Depth { get; set; }    /// <summary>    /// Gets or sets the html.    /// </summary>    public string Html { get; set; }    /// <summary>    /// Gets or sets the url.    /// </summary>    public string Url { get; set; }    #endregion  }}

DataReceivedEventArgs.cs
namespace Feng.SimpleCrawler{  using System.Collections.Generic;  using System.Threading;  /// <summary>  /// The security queue.  /// </summary>  /// <typeparam name="T">  /// Any type.  /// </typeparam>  public abstract class SecurityQueue<T>    where T : class  {    #region Fields    /// <summary>    /// The inner queue.    /// </summary>    protected readonly Queue<T> InnerQueue = new Queue<T>();    /// <summary>    /// The sync object.    /// </summary>    protected readonly object SyncObject = new object();    /// <summary>    /// The auto reset event.    /// </summary>    private readonly AutoResetEvent autoResetEvent;    #endregion    #region Constructors and Destructors    /// <summary>    /// Initializes a new instance of the <see cref="SecurityQueue{T}"/> class.    /// </summary>    protected SecurityQueue()    {      this.autoResetEvent = new AutoResetEvent(false);    }    #endregion    #region Delegates    /// <summary>    /// The before en queue event handler.    /// </summary>    /// <param name="target">    /// The target.    /// </param>    /// <returns>    /// The <see cref="bool"/>.    /// </returns>    public delegate bool BeforeEnQueueEventHandler(T target);    #endregion    #region Public Events    /// <summary>    /// The before en queue event.    /// </summary>    public event BeforeEnQueueEventHandler BeforeEnQueueEvent;    #endregion    #region Public Properties    /// <summary>    /// Gets the auto reset event.    /// </summary>    public AutoResetEvent AutoResetEvent    {      get      {        return this.autoResetEvent;      }    }    /// <summary>    /// Gets the count.    /// </summary>    public int Count    {      get      {        lock (this.SyncObject)        {          return this.InnerQueue.Count;        }      }    }    /// <summary>    /// Gets a value indicating whether has value.    /// </summary>    public bool HasValue    {      get      {        return this.Count != 0;      }    }    #endregion    #region Public Methods and Operators    /// <summary>    /// The de queue.    /// </summary>    /// <returns>    /// The <see cref="T"/>.    /// </returns>    public T DeQueue()    {      lock (this.SyncObject)      {        if (this.InnerQueue.Count > 0)        {          return this.InnerQueue.Dequeue();        }        return default(T);      }    }    /// <summary>    /// The en queue.    /// </summary>    /// <param name="target">    /// The target.    /// </param>    public void EnQueue(T target)    {      lock (this.SyncObject)      {        if (this.BeforeEnQueueEvent != null)        {          if (this.BeforeEnQueueEvent(target))          {            this.InnerQueue.Enqueue(target);          }        }        else        {          this.InnerQueue.Enqueue(target);        }        this.AutoResetEvent.Set();      }    }    #endregion  }}

SecurityQueue.cs
namespace Feng.SimpleCrawler{  /// <summary>  /// The url info.  /// </summary>  public class UrlInfo  {    #region Fields    /// <summary>    /// The url.    /// </summary>    private readonly string url;    #endregion    #region Constructors and Destructors    /// <summary>    /// Initializes a new instance of the <see cref="UrlInfo"/> class.    /// </summary>    /// <param name="urlString">    /// The url string.    /// </param>    public UrlInfo(string urlString)    {      this.url = urlString;    }    #endregion    #region Public Properties    /// <summary>    /// Gets or sets the depth.    /// </summary>    public int Depth { get; set; }    /// <summary>    /// Gets the url string.    /// </summary>    public string UrlString    {      get      {        return this.url;      }    }    /// <summary>    /// Gets or sets the status.    /// </summary>    public CrawlStatus Status { get; set; }    #endregion  }}

UrlInfo.cs
namespace Feng.SimpleCrawler{  /// <summary>  /// The url queue.  /// </summary>  public class UrlQueue : SecurityQueue<UrlInfo>  {    #region Constructors and Destructors    /// <summary>    /// Prevents a default instance of the <see cref="UrlQueue"/> class from being created.    /// </summary>    private UrlQueue()    {    }    #endregion    #region Public Properties    /// <summary>    /// Gets the instance.    /// </summary>    public static UrlQueue Instance    {      get      {        return Nested.Inner;      }    }    #endregion    /// <summary>    /// The nested.    /// </summary>    private static class Nested    {      #region Static Fields      /// <summary>      /// The inner.      /// </summary>      internal static readonly UrlQueue Inner = new UrlQueue();      #endregion    }  }}

UrlQueue.cs

5.创建windows服务.

这些工作都准备完成后,终于要来我们的重点了,我们都知道控制台程序非常不稳定,而我们的这个从博客园上面爬取文章的这个事情需要长期的进行下去,这个需要 很稳定的进行下去,所以我想起了windows服务,创建好我们的windows服务,代码如下。

using Feng.SimpleCrawler;using Feng.DbHelper;using Feng.Log;using HtmlAgilityPack;namespace Feng.Demo{  /// <summary>  /// windows服务  /// </summary>  partial class FengCnblogsService : ServiceBase  {    #region 构造函数    /// <summary>    /// 构造函数    /// </summary>    public FengCnblogsService()    {      InitializeComponent();    }     #endregion    #region 字段属性    /// <summary>    /// 蜘蛛爬虫的设置    /// </summary>    private static readonly CrawlSettings Settings = new CrawlSettings();    /// <summary>    /// 临时内存表存储数据    /// </summary>    private static DataTable dt = new DataTable();    /// <summary>    /// 关于 Filter URL:http://www.cnblogs.com/heaad/archive/2011/01/02/1924195.html    /// </summary>    private static BloomFilter<string> filter;    #endregion    #region 启动服务    /// <summary>    /// TODO: 在此处添加代码以启动服务。    /// </summary>    /// <param name="args"></param>    protected override void OnStart(string[] args)    {      ProcessStart();    }     #endregion    #region 停止服务    /// <summary>    /// TODO: 在此处添加代码以执行停止服务所需的关闭操作。    /// </summary>    protected override void OnStop()    {    }     #endregion    #region 程序开始处理    /// <summary>    /// 程序开始处理    /// </summary>    private void ProcessStart()    {      dt.Columns.Add("BlogTitle", typeof(string));      dt.Columns.Add("BlogUrl", typeof(string));      dt.Columns.Add("BlogAuthor", typeof(string));      dt.Columns.Add("BlogTime", typeof(string));      dt.Columns.Add("BlogMotto", typeof(string));      dt.Columns.Add("BlogDepth", typeof(string));      filter = new BloomFilter<string>(200000);      const string CityName = "";      #region 设置种子地址      // 设置种子地址       Settings.SeedsAddress.Add(string.Format("http://www.cnblogs.com/{0}", CityName));      Settings.SeedsAddress.Add("http://www.cnblogs.com/artech");      Settings.SeedsAddress.Add("http://www.cnblogs.com/wuhuacong/");      Settings.SeedsAddress.Add("http://www.cnblogs.com/dudu/");      Settings.SeedsAddress.Add("http://www.cnblogs.com/guomingfeng/");      Settings.SeedsAddress.Add("http://www.cnblogs.com/daxnet/");      Settings.SeedsAddress.Add("http://www.cnblogs.com/fenglingyi");      Settings.SeedsAddress.Add("http://www.cnblogs.com/ahthw/");      Settings.SeedsAddress.Add("http://www.cnblogs.com/wangweimutou/");      #endregion      #region 设置 URL 关键字      Settings.HrefKeywords.Add("a/");      Settings.HrefKeywords.Add("b/");      Settings.HrefKeywords.Add("c/");      Settings.HrefKeywords.Add("d/");      Settings.HrefKeywords.Add("e/");      Settings.HrefKeywords.Add("f/");      Settings.HrefKeywords.Add("g/");      Settings.HrefKeywords.Add("h/");      Settings.HrefKeywords.Add("i/");      Settings.HrefKeywords.Add("j/");      Settings.HrefKeywords.Add("k/");      Settings.HrefKeywords.Add("l/");      Settings.HrefKeywords.Add("m/");      Settings.HrefKeywords.Add("n/");      Settings.HrefKeywords.Add("o/");      Settings.HrefKeywords.Add("p/");      Settings.HrefKeywords.Add("q/");      Settings.HrefKeywords.Add("r/");      Settings.HrefKeywords.Add("s/");      Settings.HrefKeywords.Add("t/");      Settings.HrefKeywords.Add("u/");      Settings.HrefKeywords.Add("v/");      Settings.HrefKeywords.Add("w/");      Settings.HrefKeywords.Add("x/");      Settings.HrefKeywords.Add("y/");      Settings.HrefKeywords.Add("z/");      #endregion      // 设置爬取线程个数      Settings.ThreadCount = 1;      // 设置爬取深度      Settings.Depth = 55;      // 设置爬取时忽略的 Link,通过后缀名的方式,可以添加多个      Settings.EscapeLinks.Add("http://www.oschina.net/");      // 设置自动限速,1~5 秒随机间隔的自动限速      Settings.AutoSpeedLimit = false;      // 设置都是锁定域名,去除二级域名后,判断域名是否相等,相等则认为是同一个站点      Settings.LockHost = false;      Settings.RegularFilterExpressions.Add(@"http://([w]{3}.)+[cnblogs]+.com/");      var master = new CrawlMaster(Settings);      master.AddUrlEvent += MasterAddUrlEvent;      master.DataReceivedEvent += MasterDataReceivedEvent;      master.Crawl();    }        #endregion    #region 打印Url    /// <summary>    /// The master add url event.    /// </summary>    /// <param name="args">    /// The args.    /// </param>    /// <returns>    /// The <see cref="bool"/>.    /// </returns>    private static bool MasterAddUrlEvent(AddUrlEventArgs args)    {      if (!filter.Contains(args.Url))      {        filter.Add(args.Url);        Console.WriteLine(args.Url);        if (dt.Rows.Count > 200)        {          MssqlHelper.InsertDb(dt);          dt.Rows.Clear();        }        return true;      }      return false; // 返回 false 代表:不添加到队列中    }    #endregion    #region 解析HTML    /// <summary>    /// The master data received event.    /// </summary>    /// <param name="args">    /// The args.    /// </param>    private static void MasterDataReceivedEvent(SimpleCrawler.DataReceivedEventArgs args)    {      // 在此处解析页面,可以用类似于 HtmlAgilityPack(页面解析组件)的东东、也可以用正则表达式、还可以自己进行字符串分析      HtmlDocument doc = new HtmlDocument();      doc.LoadHtml(args.Html);      HtmlNode node = doc.DocumentNode.SelectSingleNode("//title");      string title = node.InnerText;      HtmlNode node2 = doc.DocumentNode.SelectSingleNode("//*[@id='post-date']");      string time = node2.InnerText;      HtmlNode node3 = doc.DocumentNode.SelectSingleNode("//*[@id='topics']/div/div[3]/a[1]");      string author = node3.InnerText;      HtmlNode node6 = doc.DocumentNode.SelectSingleNode("//*[@id='blogTitle']/h2");      string motto = node6.InnerText;      MssqlHelper.GetData(title, args.Url, author, time, motto, args.Depth.ToString(), dt);      LogHelper.WriteLog(title);      LogHelper.WriteLog(args.Url);      LogHelper.WriteLog(author);      LogHelper.WriteLog(time);      LogHelper.WriteLog(motto == "" ? "null" : motto);      LogHelper.WriteLog(args.Depth + "&dt.Rows.Count=" + dt.Rows.Count);      //每次超过100条数据就存入数据库,可以根据自己的情况设置数量      if (dt.Rows.Count > 100)      {        MssqlHelper.InsertDb(dt);        dt.Rows.Clear();      }    }    #endregion  }}

这里我们用爬虫从博客园爬取来了博文,我们需要用这个HtmlAgilityPack第三方工具来解析出我们需要的字段,博文标题,博文作者,博文URL,等等一些信息。同时我们可以设置服务的一些信息

在网络爬虫中,我们要设置一些参数,设置种子地址,URL关键字,还有爬取的深度等等,这些工作都完成后,我们就只需要安装我们的windows服务,就大功告成了。嘿嘿...

 6.0安装windows服务

在这里我们采用vs自带的工具来安装windows服务。

安装成功后,打开我们的windows服务就可以看到我们安装的windows服务。

同时可以查看我们的日志文件,查看我们爬取的博文解析出来的信息。如下图所示。

这个时候去查看我们的数据库,我的这个服务已经运行了一天。。。

 如果你觉得本文不错的话,帮我推荐一下,本人能力有限,文中如有不妥之处,欢迎拍砖,如果需要源码的童鞋,可以留下你的邮箱...