(转)lucene.net和（pangu）盘古分词 搜索引擎的简单实现

本文转载自：http://blog.csdn.net/dongdongleng/article/details/6058416

这篇文章是介绍lucene.net和盘古分词的简单的实现调用  。建立索引，搜索，盘古分词的基类如下：

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using Lucene.Net.Index;
using Lucene.Net.Documents;
using Lucene.Net.QueryParsers;
using Lucene.Net.Analysis;
using Lucene.Net.Search;
using Lucene.Net.Analysis.Standard;
using PanGu;
using Lucene.Net.Analysis.PanGu;
using StringBulider;
using System.Text;
using System.Collections;
using System.Collections.Generic;

/// <summary>
///辅导资料的搜索逻辑 的摘要说明
/// </summary>
public class DataSearch
{
    public DataSearch()
    {
        //
        //TODO: 在此处添加构造函数逻辑
        //
    }
     A_DB_Conn db = null;
    string index = System.Web.HttpContext.Current.Server.MapPath("~/Gongxin/DataIndex");//索引路径
    string wordPath = System.Web.HttpContext.Current.Server.MapPath("~/Dictionaries");//字典路径
    //用于存储检索出数据总数
    private int _count;

    public int Count
    {
        get { return _count; }
        set { _count = value; }
    }
    //搜索关键字
    private string _keyword;

    public string KeyWord
    {
        get { return _keyword;}
        set{_keyword = value;}
    }
    //搜索时间
    private double  _time;
    public double Time
    {
        get { return _time; }
        set { _time = value; }
    }
    /// <summary>
    /// 得到数据结果集
    /// </summary>
    /// <returns></returns>
    public DataTable GetDS()
    {
        db = new A_DB_Conn();
        string sql = "select  N_id,N_title,N_datetime,N_Content from N_Newinfo where N_ifkping=1 and N_id=12 order by N_datetime desc";
        DataTable dataTable = null;
        try
        {
            dataTable = db.GetDataSet(sql).Tables[0];
        }
        catch
        {
            dataTable = null;
        }
        finally
        {
            db.close();
            db.Dispose();
        }
        return dataTable;
    }

    /// <summary>
    /// 添加索引域
    /// </summary>
    /// <param name="writer"></param>
    /// <param name="dataTable"></param>
    public void AddDocument(IndexWriter writer, DataTable dataTable)
    {
        for (int i = 0; i < dataTable.Rows.Count; i++)
        {
            Document doc = new Document();
            doc.Add(new Field("ID", dataTable.Rows[i]["N_id"].ToString(),Field.Store.YES,Field.Index.TOKENIZED));
            doc.Add(new Field("N_title",StringCheck.SqlQueryDecode(dataTable.Rows[i]["N_title"].ToString()),Field.Store.YES,Field.Index.TOKENIZED));
            doc.Add(new Field("N_datetime", dataTable.Rows[i]["N_datetime"].ToString(),Field.Store.YES,Field.Index.TOKENIZED));
            if (StringCheck.SqlQueryDecode(dataTable.Rows[i]["N_Content"].ToString()).Length > 100)
            {
                doc.Add(new Field("N_Content", StringCheck.SqlQueryDecode(dataTable.Rows[i]["N_Content"].ToString()).Replace("<p>","").Replace("</p>","").Substring(0, 200), Field.Store.YES, Field.Index.TOKENIZED));
            }
            else
            {
                doc.Add(new Field("N_Content", StringCheck.SqlQueryDecode(dataTable.Rows[i]["N_Content"].ToString()).Replace("<p>", "").Replace("</p>", ""), Field.Store.YES, Field.Index.TOKENIZED));
            }
            writer.AddDocument(doc);
        }
    }

    /// <summary>
    /// 建立索引
    /// </summary>
    public void Index()
    {
        PanGu.Segment.Init();
        PanGuAnalyzer analyzer = new PanGuAnalyzer();
        IndexWriter writer = new IndexWriter(index, analyzer, true);
        DataTable dataTable = GetDS();
        AddDocument(writer, dataTable);
        writer.Optimize();
        writer.Close();
    }

    /// <summary>
    /// 对药搜索的词进行分词
    /// </summary>
    /// <param name="keyWords">要收索的词</param>
    /// <param name="ktTokenizer">分词对象</param>
    /// <returns>分词后的结果</returns>
    public string GetKeyWordSplitBySpace(string keyWords, PanGuTokenizer ktTokenizer)
    {
        StringBuilder builder = new StringBuilder();
        ICollection<WordInfo> words = ktTokenizer.SegmentToWordInfos(keyWords);
        foreach(WordInfo word in words)
        {
            if (word == null)
            {
                continue;
            }
            KeyWord = KeyWord + word+",";
            builder.AppendFormat("{0}^{1}",word.Word,(int)Math.Pow(3,word.Rank));
        }
        KeyWord = KeyWord.Substring(0, KeyWord.Length - 1);
        return builder.ToString().Trim();
    }

    /// <summary>
    /// 检索信息
    /// </summary>
    /// <param name="keyWord">检索关键字</param>
    /// <param name="pageNumber">当前第几条</param>
    /// <param name="pageSize">每页显示的条数</param>
    /// <returns></returns>
    public string Search(string keyWord, int pageNumber, int pageSize)
    {
        string word = GetKeyWordSplitBySpace(keyWord, new PanGuTokenizer());

        IndexSearcher search = new IndexSearcher(index);
        StringBuilder builder = new StringBuilder();
        PanGuAnalyzer analyzer = new PanGuAnalyzer(true);
        //多字段搜索字段
        MultiFieldQueryParser parser = new MultiFieldQueryParser(new string[] { "N_title" },analyzer);
        //分词
        Query query = parser.Parse(word);
        Hits hits = search.Search(query);
        Count = hits.Length();
        int num = 0;//记录每页最后一条
        if (Count < pageNumber + pageSize)
        {
            num = Count;
        }
        else
        {
            num = pageSize + pageNumber;
        }
        DateTime  begin = DateTime.Now;
        for (int i = pageNumber; i < num; i++)
        {
            Document doc = hits.Doc(i);
            //创建HTMLFormatter,参数为高亮搜索词的HTML代码
            PanGu.HighLight.SimpleHTMLFormatter simpleHTMLFormatter = new PanGu.HighLight.SimpleHTMLFormatter("<font color='red'>", "</font>");
            //创建高亮，输入HTML代码和 盘古对象Semgent
            PanGu.HighLight.Highlighter highter = new PanGu.HighLight.Highlighter(simpleHTMLFormatter, new Segment());
            //设置每个摘要字段的字符数
            highter.FragmentSize = 200;
            string title = highter.GetBestFragment(keyWord, doc.Get("N_title"));
            builder.Append("<div class='sea_h_list'>");
            if (!string.IsNullOrEmpty(title))
            {
                builder.Append("<h2><a href="D_NewBody.aspx?gxjy=" + UrlEncrpt.Encrypt(doc.Get("ID")) + "" mce_href="D_NewBody.aspx?gxjy=" + UrlEncrpt.Encrypt(doc.Get("ID")) + "" target='_blank'>" + highter.GetBestFragment(keyWord, doc.Get("N_title")) + "</a></h2>");
            }
            else
            {
                builder.Append("<h2>" + doc.Get("N_title") + "</h2>");
            }
            builder.Append(doc.Get("N_Content"));
            DateTime time = Convert.ToDateTime(doc.Get("N_datetime"));
            builder.Append("<div>"+time.ToString("yyyy-MM-dd")+"</div>");
            builder.Append("</div>");

        }
        DateTime end = DateTime.Now;
        double  ts = (end - begin).TotalMilliseconds;
        Time =ts / 1000.000;
        search.Close();//关闭检索器
        return builder.ToString();
    }
}

前台可以用一个button调用一个button事件来生成索引

前台生成索引事件如下。

protected void Button1_Click(object sender, EventArgs e)
    {
        search = new NewsSearch();
        search.Index();
        Response.Write("<Script>alert('索引生成成功！')</Script>");
    }

索引生成成功后，就可以进行搜索了，本人实现搜索的功能时调用了AspNetPager分页控件，具体的搜索的方法如下：

public void GetInfoList(string keyWord)
  {
      try
      {
          search = new NewsSearch();
          Stopwatch sw = new Stopwatch();
          sw.Start();
          InfoList = search.Search(keyWord, (this.AspNetPager1.CurrentPageIndex - 1) * this.AspNetPager1.PageSize, this.AspNetPager1.PageSize);
          sw.Stop();
          time = (sw.ElapsedMilliseconds / 1000.000).ToString();//显示所用搜索时间
          if (InfoList.Trim().Length == 0)
          {
              InfoList = "<div class='rig01_center red'>暂无搜索信息。</div>";
          }
          this.AspNetPager1.RecordCount = search.Count;
          count = search.Count.ToString();//搜索的条数
          strkeyWord = search.KeyWord;//显示搜索关键字

      }
      catch
      {
          Response.Redirect("404.html");
      }

  }

其中 Stopwatch使用了计算搜索所用的时间，将它复制到time 全局变量中,count 全局变量时用来存储搜索的条数。

搜索出来数据后，前台页面用<%=count%><%=time%> <%=InfoList%>

调用即可。

前台显示效果： 

本文只是简单的实现了lucene.net 和盘古分词,仅供大家学习，有不足的地方还请见谅，有疑问随时联系，谢谢！