Lucene.Net+盘古分词->开发自己的搜索引擎

2022-09-22 17:33:41

//封装类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Lucene.Net.Analysis;
using Lucene.Net.Index;
using Lucene.Net.Documents;
using System.Reflection;
using Lucene.Net.QueryParsers;
using Lucene.Net.Search;
namespace SearchTest
{
 /// <summary>
 /// 盘古分词在lucene.net中的使用帮助类
 /// 调用PanGuLuceneHelper.instance
 /// </summary>
 public class PanGuLuceneHelper
 {
 private PanGuLuceneHelper() { }

#region 单一实例
 private static PanGuLuceneHelper _instance = null;
 /// <summary>
 /// 单一实例
 /// </summary>
 public static PanGuLuceneHelper instance
 {
 get
 {
 if (_instance == null) _instance = new PanGuLuceneHelper();
 return _instance;
 }
 }
 #endregion

#region 分词测试
 /// <summary>
 /// 分词测试
 /// </summary>
 /// <param name="keyword"></param>
 /// <returns></returns>
 public string Token(string keyword)
 {
 string ret = "";
 System.IO.StringReader reader = new System.IO.StringReader(keyword);
 Lucene.Net.Analysis.TokenStream ts = analyzer.TokenStream(keyword, reader);
 bool hasNext = ts.IncrementToken();
 Lucene.Net.Analysis.Tokenattributes.ITermAttribute ita;
 while (hasNext)
 {
 ita = ts.GetAttribute<Lucene.Net.Analysis.Tokenattributes.ITermAttribute>();
 ret += ita.Term + "|";
 hasNext = ts.IncrementToken();
 }
 ts.CloneAttributes();
 reader.Close();
 analyzer.Close();
 return ret;
 }
 #endregion

#region 创建索引
 /// <summary>
 /// 创建索引
 /// </summary>
 /// <param name="datalist"></param>
 /// <returns></returns>
 public bool CreateIndex(List<MySearchUnit> datalist)
 {
 IndexWriter writer = null;
 try
 {
 writer = new IndexWriter(directory_luce, analyzer, false, IndexWriter.MaxFieldLength.LIMITED);//false表示追加（true表示删除之前的重新写入）
 }
 catch
 {
 writer = new IndexWriter(directory_luce, analyzer, true, IndexWriter.MaxFieldLength.LIMITED);//false表示追加（true表示删除之前的重新写入）
 }
 foreach (MySearchUnit data in datalist)
 {
 CreateIndex(writer, data);
 }
 writer.Optimize();
 writer.Dispose();
 return true;
 }

public bool CreateIndex(IndexWriter writer, MySearchUnit data)
        {
            try
            {

if (data == null) return false;
Document doc = new Document();
Type type = data.GetType();//assembly.GetType("Reflect_test.PurchaseOrderHeadManageModel", true, true); //命名空间名称 + 类名

//创建类的实例
 //object obj = Activator.CreateInstance(type, true);
 //获取公共属性
 PropertyInfo[] Propertys = type.GetProperties();
 for (int i = 0; i < Propertys.Length; i++)
 {
 //Propertys[i].SetValue(Propertys[i], i, null); //设置值
 PropertyInfo pi = Propertys[i];
 string name=pi.Name;
 object objval = pi.GetValue(data, null);
 string value = objval == null ? "" : objval.ToString(); //值
 if (name == "id" || name=="flag" )//id在写入索引时必是不分词，否则是模糊搜索和删除，会出现混乱
 {
 doc.Add(new Field(name, value, Field.Store.YES, Field.Index.NOT_ANALYZED));//id不分词
 }
 else
 {
 doc.Add(new Field(name, value, Field.Store.YES, Field.Index.ANALYZED));
 }
 }
 writer.AddDocument(doc);
 }
 catch (System.IO.FileNotFoundException fnfe)
 {
 throw fnfe;
 }
 return true;
 }
 #endregion

#region 在title和content字段中查询数据
 /// <summary>
 /// 在title和content字段中查询数据
 /// </summary>
 /// <param name="keyword"></param>
 /// <returns></returns>
 public List<MySearchUnit> Search(string keyword)
 {

string[] fileds = { "title", "content" };//查询字段
 //Stopwatch st = new Stopwatch();
 //st.Start();
 QueryParser parser = null;// new QueryParser(Lucene.Net.Util.Version.LUCENE_30, field, analyzer);//一个字段查询
 parser = new MultiFieldQueryParser(version, fileds, analyzer);//多个字段查询
 Query query = parser.Parse(keyword);
 int n = 1000;
 IndexSearcher searcher = new IndexSearcher(directory_luce, true);//true-表示只读
 TopDocs docs = searcher.Search(query, (Filter)null, n);
 if (docs == null || docs.TotalHits == 0)
 {
 return null;
 }
 else
 {
 List<MySearchUnit> list = new List<MySearchUnit>();
 int counter = 1;
 foreach (ScoreDoc sd in docs.ScoreDocs)//遍历搜索到的结果
 {
 try
 {
 Document doc = searcher.Doc(sd.Doc);
 string id = doc.Get("id");
 string title = doc.Get("title");
 string content = doc.Get("content");
 string flag = doc.Get("flag");
 string imageurl = doc.Get("imageurl");
 string updatetime = doc.Get("updatetime");

string createdate = doc.Get("createdate");
 PanGu.HighLight.SimpleHTMLFormatter simpleHTMLFormatter = new PanGu.HighLight.SimpleHTMLFormatter("", "");
 PanGu.HighLight.Highlighter highlighter = new PanGu.HighLight.Highlighter(simpleHTMLFormatter, new PanGu.Segment());
 highlighter.FragmentSize = 50;
 content = highlighter.GetBestFragment(keyword, content);
 string titlehighlight = highlighter.GetBestFragment(keyword, title);
 if (titlehighlight != "") title = titlehighlight;
 list.Add(new MySearchUnit(id, title, content, flag,imageurl, updatetime));
 }
 catch (Exception ex)
 {
 Console.WriteLine(ex.Message);
 }
 counter++;
 }
 return list;
 }
 //st.Stop();
 //Response.Write("查询时间：" + st.ElapsedMilliseconds + " 毫秒 ");

}
#endregion

#region 在不同的分类下再根据title和content字段中查询数据(分页)
 /// <summary>
 /// 在不同的类型下再根据title和content字段中查询数据(分页)
 /// </summary>
 /// <param name="_flag">分类,传空值查询全部</param>
 /// <param name="keyword"></param>
 /// <param name="PageIndex"></param>
 /// <param name="PageSize"></param>
 /// <param name="TotalCount"></param>
 /// <returns></returns>
 public List<MySearchUnit> Search(string _flag,string keyword, int PageIndex, int PageSize, out int TotalCount)
 {
 if (PageIndex < 1) PageIndex = 1;
 //Stopwatch st = new Stopwatch();
 //st.Start();
 BooleanQuery bq = new BooleanQuery();
 if (_flag != "")
 {
 QueryParser qpflag = new QueryParser(version, "flag", analyzer);
 Query qflag = qpflag.Parse(_flag);
 bq.Add(qflag, Occur.MUST);//与运算
 }
 if (keyword != "")
 {
 string[] fileds = { "title", "content" };//查询字段
 QueryParser parser = null;// new QueryParser(version, field, analyzer);//一个字段查询
 parser = new MultiFieldQueryParser(version, fileds, analyzer);//多个字段查询
 Query queryKeyword = parser.Parse(keyword);
 bq.Add(queryKeyword, Occur.MUST);//与运算
 }

 TopScoreDocCollector collector = TopScoreDocCollector.Create(PageIndex * PageSize, false);
 IndexSearcher searcher = new IndexSearcher(directory_luce, true);//true-表示只读
 searcher.Search(bq, collector);
 if (collector == null || collector.TotalHits == 0)
 {
 TotalCount = 0;
 return null;
 }
 else
 {
 int start = PageSize * (PageIndex - 1);
 //结束数
 int limit = PageSize;
 ScoreDoc[] hits = collector.TopDocs(start, limit).ScoreDocs;
 List<MySearchUnit> list = new List<MySearchUnit>();
 int counter = 1;
 TotalCount = collector.TotalHits;
 foreach (ScoreDoc sd in hits)//遍历搜索到的结果
 {
 try
 {
 Document doc = searcher.Doc(sd.Doc);
 string id = doc.Get("id");
 string title = doc.Get("title");
 string content = doc.Get("content");
 string flag = doc.Get("flag");
 string imageurl = doc.Get("imageurl");
 string updatetime = doc.Get("updatetime");

PanGu.HighLight.SimpleHTMLFormatter simpleHTMLFormatter = new PanGu.HighLight.SimpleHTMLFormatter("", "");
 PanGu.HighLight.Highlighter highlighter = new PanGu.HighLight.Highlighter(simpleHTMLFormatter, new PanGu.Segment());
 highlighter.FragmentSize = 50;
 content = highlighter.GetBestFragment(keyword, content);
 string titlehighlight = highlighter.GetBestFragment(keyword, title);
 if (titlehighlight != "") title = titlehighlight;
 list.Add(new MySearchUnit(id, title, content, flag,imageurl, updatetime));
 }
 catch (Exception ex)
 {
 Console.WriteLine(ex.Message);
 }
 counter++;
 }
 return list;
 }
 //st.Stop();
 //Response.Write("查询时间：" + st.ElapsedMilliseconds + " 毫秒 ");

}
#endregion

#region 删除索引数据（根据id）
 /// <summary>
 /// 删除索引数据（根据id）
 /// </summary>
 /// <param name="id"></param>
 /// <returns></returns>
 public bool Delete(string id)
 {
 bool IsSuccess = false;
 Term term = new Term("id", id);
 //Analyzer analyzer = new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30);
 //Version version = new Version();
 //MultiFieldQueryParser parser = new MultiFieldQueryParser(version, new string[] { "name", "job" }, analyzer);//多个字段查询
 //Query query = parser.Parse("小王");

//IndexReader reader = IndexReader.Open(directory_luce, false);
 //reader.DeleteDocuments(term);
 //Response.Write("删除记录结果： " + reader.HasDeletions + " ");
 //reader.Dispose();

IndexWriter writer = new IndexWriter(directory_luce, analyzer, false, IndexWriter.MaxFieldLength.LIMITED);
            writer.DeleteDocuments(term); // writer.DeleteDocuments(term)或者writer.DeleteDocuments(query);
            ////writer.DeleteAll();
            writer.Commit();
            //writer.Optimize();//
            IsSuccess = writer.HasDeletions();
            writer.Dispose();
            return IsSuccess;
        }
        #endregion

#region 删除全部索引数据
 /// <summary>
 /// 删除全部索引数据
 /// </summary>
 /// <returns></returns>
 public bool DeleteAll()
 {
 bool IsSuccess = true;
 try
 {
 IndexWriter writer = new IndexWriter(directory_luce, analyzer, false, IndexWriter.MaxFieldLength.LIMITED);
 writer.DeleteAll();
 writer.Commit();
 //writer.Optimize();//
 IsSuccess = writer.HasDeletions();
 writer.Dispose();
 }
 catch
 {
 IsSuccess = false;
 }
 return IsSuccess;
 }
 #endregion

#region directory_luce
 private Lucene.Net.Store.Directory _directory_luce = null;
 /// <summary>
 /// Lucene.Net的目录-参数
 /// </summary>
 public Lucene.Net.Store.Directory directory_luce
 {
 get
 {
 if (_directory_luce == null) _directory_luce = Lucene.Net.Store.FSDirectory.Open(directory);
 return _directory_luce;
 }
 }
 #endregion

#region directory
 private System.IO.DirectoryInfo _directory = null;
 /// <summary>
 /// 索引在硬盘上的目录
 /// </summary>
 public System.IO.DirectoryInfo directory
 {
 get
 {
 if (_directory == null)
 {
 string dirPath = AppDomain.CurrentDomain.BaseDirectory + "SearchIndex";
 if (System.IO.Directory.Exists(dirPath) == false) _directory = System.IO.Directory.CreateDirectory(dirPath);
 else _directory = new System.IO.DirectoryInfo(dirPath);
 }
 return _directory;
 }
 }
 #endregion

#region analyzer
 private Analyzer _analyzer = null;
 /// <summary>
 /// 分析器
 /// </summary>
 public Analyzer analyzer
 {
 get
 {
 //if (_analyzer == null)
 {
 _analyzer = new Lucene.Net.Analysis.PanGu.PanGuAnalyzer();//盘古分词分析器
 //_analyzer = new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30);//标准分析器
 }
 return _analyzer;
 }
 }
 #endregion

#region version
 private static Lucene.Net.Util.Version _version = Lucene.Net.Util.Version.LUCENE_30;
 /// <summary>
 /// 版本号枚举类
 /// </summary>
 public Lucene.Net.Util.Version version
 {
 get
 {
 return _version;
 }
 }
 #endregion
 }

#region 索引的一个行单元，相当于数据库中的一行数据
 /// <summary>
 /// 索引的一个行单元，相当于数据库中的一行数据
 /// </summary>
 public class MySearchUnit
 {
 public MySearchUnit(string _id, string _title, string _content, string _flag, string _imageurl, string _updatetime)
 {
 this.id = _id;
 this.title = _title;
 this.content = _content;
 this.flag = _flag;
 this.imageurl = _imageurl;
 this.updatetime = _updatetime;
 }
 /// <summary>
 /// 唯一的id号
 /// </summary>
 public string id { get; set; }
 /// <summary>
 /// 标题
 /// </summary>
 public string title { get; set; }
 /// <summary>
 /// 内容
 /// </summary>
 public string content { get; set; }
 /// <summary>
 /// 其他信息
 /// </summary>
 public string flag { get; set; }
 /// <summary>
 /// 图片路径
 /// </summary>
 public string imageurl { get; set; }
 /// <summary>
 /// 时间
 /// </summary>
 public string updatetime { get; set; }
 }
 #endregion
}

原文地址：http://blog.csdn.net/pukuimin1226/article/details/17558247

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