LuceneNet的使用

 

先建立索引，再查询，速度很快。

索引花费的时间比较多，但还可以接受，200M的文本需要1分多钟，40G的文本需要4个小时多。

刚开始我用 2.9版本的，是选择将文本也保存在索引中，占据的空间比原先的文本2倍多。

而且发现如果里面的邮箱地址不带@后面无法查询出来，也许是所用的分词的关系，也不知道怎样才可以自定义分隔符。

后来改用了4.8版本，索引的空间只比原先的文本大一点点，而且不带@的关键字也可以查询出来。

但还是有个问题，查询出来的内容中文是乱码，也无法用中文查询。

 

 

无论是 NLuke 还是 Luke ， 都没法成功打开索引文件。

IndexWriter 构造函数使用了另一个重载，即第三个参数为 bool，如果为 true 表示不存在就创建、存在就覆盖，为 false 表示不存在就出错、存在就追加。这个不方便，因为我们需要的是：不存在就创建、存在就追加，怎样才能实现这个功能呢？省略掉，就实现这个功能了。

 

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112

void Main()<br>{<br> <br> string idxpath = @"D:\data\DB\txt\index\";<br> string dir = @"D:\data\DB\txt\search\tianya\";<br> //!!怎样用@分词？<br> string keyword = "zhaoshu0997";<br> Utils.FullSearch.FileHelper filehelper= new Utils.FullSearch.FileHelper(idxpath);<br> //filehelper.BuildIndex(dir);<br> Utils.FullSearch.SearchResults results = filehelper.Search(keyword);<br> Console.WriteLine($"{keyword.ToString()}");<br> results.Dump();<br>}<br><br>namespace Utils.FullSearch {     public class SearchResults{         public int TotalHits{get;set;}         public List<Hit> SearchContents{get;set;}     }           public class Hit{         public float Score{get;set;}         public string Content{get;set;}     }           public class FileHelper     {         private const LuceneVersion MATCH_LUCENE_VERSION= LuceneVersion.LUCENE_48;         private const string Field_Name= "content";         private const int Results_Per_Page = 10;         //private  IndexWriter writer;         private  StandardAnalyzer analyzer;         private  QueryParser queryParser;         //private  SearcherManager searchManager;         private string _indexPath;                   private StandardAnalyzer SetupAnalyzer() => new StandardAnalyzer(MATCH_LUCENE_VERSION);         private QueryParser SetupQueryParser(StandardAnalyzer analyzer) => new QueryParser(MATCH_LUCENE_VERSION, Field_Name, analyzer);                   public FileHelper(string indexPath)         {             analyzer = SetupAnalyzer();             queryParser = SetupQueryParser(analyzer);             _indexPath = indexPath;                       }                   public void BuildIndex(string dir)         {             var watch = Stopwatch.StartNew();             List<string> fpaths = FindFile(dir);                           IndexWriter writer = new IndexWriter(FSDirectory.Open(_indexPath), new IndexWriterConfig(MATCH_LUCENE_VERSION, analyzer));             foreach(string fpath in fpaths){                 string[] contents = File.ReadAllLines(fpath, Encoding.UTF8);                 foreach(string content in contents){                     Document doc = new Document                     {                                        new TextField(Field_Name, content, Field.Store.YES)                     };                     writer.AddDocument(doc);                 }                 ($"index time for {fpath}:{watch.ElapsedMilliseconds/1000.0}second").Dump();             }                             writer.Flush(true, true);             writer.Commit();             writer.Dispose();             watch.Stop();             ($"index time for {dir}:{watch.ElapsedMilliseconds/1000.0}second").Dump();         }                   public static List<string> FindFile(string sSourcePath)         {             List<String> list = new List<string>();             DirectoryInfo theFolder = new DirectoryInfo(sSourcePath);             FileInfo[] thefileInfo = theFolder.GetFiles("*.*", SearchOption.TopDirectoryOnly);             foreach (FileInfo NextFile in thefileInfo)  //遍历文件                 list.Add(NextFile.FullName);                  DirectoryInfo[] dirInfo = theFolder.GetDirectories();                 foreach (DirectoryInfo NextFolder in dirInfo)                 {                     //list.Add(NextFolder.ToString());                     FileInfo[] fileInfo = NextFolder.GetFiles("*.*", SearchOption.AllDirectories);                     foreach (FileInfo NextFile in fileInfo)  //遍历文件                         list.Add(NextFile.FullName);                 }                       return list;         }                       public  SearchResults Search(string queryString)         {             var watch = Stopwatch.StartNew();             Query query = queryParser.Parse(queryString);             IndexWriter writer = new IndexWriter(FSDirectory.Open(_indexPath), new IndexWriterConfig(MATCH_LUCENE_VERSION, analyzer));             SearcherManager searchManager = new SearcherManager(writer, true, null);             searchManager.MaybeRefreshBlocking();             IndexSearcher searcher = searchManager.Acquire();                       try             {                 TopDocs topdDocs = searcher.Search(query, Results_Per_Page);                         SearchResults searchResults = new SearchResults() { TotalHits = topdDocs.TotalHits, SearchContents = new List<Hit>() };                 foreach (var result in topdDocs.ScoreDocs)                 {                     Document document = searcher.Doc(result.Doc);                     Hit searchResult = new Hit                     {                         Score = result.Score,                         Content = document.GetField(Field_Name)?.GetStringValue()                     };                     searchResults.SearchContents.Add(searchResult);                 }                 ($"search time for {queryString}:{watch.ElapsedMilliseconds/1000.0}second").Dump();                 return searchResults;             }             finally             {                 searchManager.Release(searcher);                 searcher = null;             }                       }     } }