基于lucene.net 和ICTCLAS2014的站内搜索的实现2

分词系统建立完毕，这是基础也是核心，后面我们建立索引要用到分词系统。

下面依次讲解索引的建立，索引的查找。

分词系统建立完毕，这是基础也是核心，后面我们建立索引要用到分词系统。下面依次讲解索引的建立，索引的查找。

         索引的建立采用的是倒排序，原理就是遍历所有的文本，对其进行分词，然后把分的词汇建立索引表。形式类似如下：

词汇          出现词汇的篇章1，篇章2，篇章3……

         建立索引的时候要注意这样的Document，Field这俩术语。Document代表的是一个文档，它里面包含一个或者多个Filed，Field表示的就是一种域，你可以在一个Document里面添加各种各样的域，名字自己起，但是关于文档的内容一定要加进去，方式如下所示：

doc.Add(new Field("contents", str, Field.Store.YES, Field.Index.ANALYZED,Field.TermVector.WITH_POSITIONS_OFFSETS));

整个索引的建立如下所示：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;
using Lucene.Net.Analysis;
using Lucene.Net.Analysis.Standard;
using Lucene.Net.Index;
using Lucene.Net.Documents;
using Lucene.Net.Search;
using Lucene.Net.Analysis.DChinese;

using Version = Lucene.Net.Util.Version;
using FSDirectory = Lucene.Net.Store.FSDirectory;
using NativeFSLockFactory = Lucene.Net.Store.NativeFSLockFactory;

namespace WebApplication6
{
    public class IndexFiles
    {
        

        public static bool CreateIndexFromFile(DirectoryInfo docDir, DirectoryInfo IndexDir)
        {
            string strUserDicPath = System.AppDomain.CurrentDomain.BaseDirectory;
            string strTestDic = strUserDicPath;
            HashSet<string> lstStopWords = new HashSet<string>();

            strUserDicPath = strUserDicPath + "UserDictionary\\StopWords.txt";
            string[] strs = null;

            StreamWriter sw = new StreamWriter(strTestDic + "UserDictionary\\StopTest.txt");
            using (StreamReader strReader = new StreamReader(strUserDicPath))
            {
                string strLine;
                while ((strLine = strReader.ReadLine()) != null)
                {
                    strLine = strLine.Trim();
                    strs = strLine.Split();
                    foreach (string str in strs)
                    {
                        lstStopWords.Add(str);
                        sw.WriteLine(str);
                        
                    }
                }
                strReader.Close();
                sw.Close();
            }

            bool bExist = File.Exists(docDir.FullName) || Directory.Exists(docDir.FullName);
            if (!bExist)
            {
                return false;
            }

            //using (IndexWriter writer = new IndexWriter(FSDirectory.Open(IndexDir), new DChineseAnalyzer(Version.LUCENE_30), true, IndexWriter.MaxFieldLength.LIMITED) )
            //IndexWriter writer = new IndexWriter(fsDirrctory, new StandardAnalyzer(Version.LUCENE_30), true, IndexWriter.MaxFieldLength.LIMITED);
            
            FSDirectory fsDirrctory = FSDirectory.Open(IndexDir, new NativeFSLockFactory());
            Analyzer analyzer = new DChineseAnalyzer(Version.LUCENE_30,lstStopWords);
            IndexWriter writer = new IndexWriter(fsDirrctory, analyzer, true, IndexWriter.MaxFieldLength.LIMITED);
            try
            {
                IndexDirectory(writer, docDir);
                writer.Optimize();
                writer.Commit();
            }
            finally
            {
                writer.Dispose();
                fsDirrctory.Dispose();
            }
            
            return true;
        }

        internal static void IndexDirectory(IndexWriter writer, DirectoryInfo directory)
        {
            foreach (var subDirectory in directory.GetDirectories())
                IndexDirectory(writer, subDirectory);

            foreach (var file in directory.GetFiles())
                IndexDocs(writer, file);
        }

        internal static void IndexDocs(IndexWriter writer, FileInfo file)
        {
            Console.Out.WriteLine("adding " + file);

            try
            {
                writer.AddDocument(Document(file));
            }
            catch (FileNotFoundException)
            {
                // At least on Windows, some temporary files raise this exception with an
                // "access denied" message checking if the file can be read doesn't help.
            }
            catch (UnauthorizedAccessException)
            {
                // Handle any access-denied errors that occur while reading the file.    
            }
            catch (IOException)
            {
                // Generic handler for any io-related exceptions that occur.
            }
        }

        public static Document Document(FileInfo f)
        {

            // make a new, empty document
            Document doc = new Document();

            // Add the path of the file as a field named "path".  Use a field that is 
            // indexed (i.e. searchable), but don't tokenize the field into words.
            doc.Add(new Field("path", f.FullName, Field.Store.YES, Field.Index.NOT_ANALYZED));

            // Add the last modified date of the file a field named "modified".  Use 
            // a field that is indexed (i.e. searchable), but don't tokenize the field
            // into words.
            doc.Add(new Field("modified", DateTools.TimeToString(f.LastWriteTime.Millisecond, DateTools.Resolution.MINUTE), Field.Store.YES, Field.Index.NOT_ANALYZED));

            // Add the contents of the file to a field named "contents".  Specify a Reader,
            // so that the text of the file is tokenized and indexed, but not stored.
            // Note that FileReader expects the file to be in the system's default encoding.
            // If that's not the case searching for special characters will fail.

            string str = File.ReadAllText(f.FullName);
            //doc.Add(new Field("contents", new StreamReader(f.FullName, System.Text.Encoding.UTF8)));
            doc.Add(new Field("contents", str, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS));

            // return the document
            return doc;
        }
    }
}

查找的实现：

         Lucene.net中有多种多样的查找类，但是如果要实现多条件查询就要使用PhraseQuery

类。通过搜索函数把搜索结果放到容器里面。

         最后结果的呈现时候，我们把搜索结果放到列表里面，如果还要显示关键词加亮，那么就需要做一点额外的工作。在这里我是通过ColorWord这个类实现的。具体的搜索代码如下所示：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;
using Lucene.Net.Analysis;
using Lucene.Net.Analysis.DChinese;
using Lucene.Net.Documents;
using Lucene.Net.QueryParsers;
using Lucene.Net.Index;
using Lucene.Net.Search;


using FSDirectory = Lucene.Net.Store.FSDirectory;
using NoLockFactory = Lucene.Net.Store.NoLockFactory;
using Version = Lucene.Net.Util.Version;


namespace WebApplication6
{
    public static class SearchFiles
    {
        public static List<ItemList> SearchIndex(DirectoryInfo dirIndex, List<string> termList)
        {
            FSDirectory     dirFS    = FSDirectory.Open(dirIndex, new NoLockFactory());
            IndexReader     reader   = IndexReader.Open(dirFS,true);
            IndexSearcher   searcher = new IndexSearcher(reader);
            Analyzer        analyzer = new DChineseAnalyzer(Version.LUCENE_30);
            PhraseQuery     query    = new PhraseQuery();


            foreach (string word in termList)
            {
                query.Add( new Term("contents",word) );
            }
            query.Slop = 100;


            TopScoreDocCollector collector = TopScoreDocCollector.Create(1000, true);
            searcher.Search(query,collector);
            ScoreDoc[] hits = collector.TopDocs().ScoreDocs;
            List<ItemList> lstResult = new List<ItemList>();
            for (int i = 0; i < hits.Length; i++)
            {
                Document doc = new Document();
                doc = searcher.Doc(hits[i].Doc);
                ItemList item = new ItemList();
                //item.ItemContent = doc.Get("contents");
                item.ItemContent = ColorWord.addColor(doc.Get("contents"),termList);
                item.ItemPath = doc.Get("path");
                lstResult.Add(item);
            }
            return lstResult;
        }
    }
}

最终的代码下载地址:下载

基于lucene.net 和ICTCLAS2014的站内搜索的实现2,古老的榕树,5-wow.com