Lucene全文检索-从零开始

Posted 2020-08-11

1.索引的追加

索引的追加是比较耗时的，如果等执行完毕再向用户返回结果，长时间的等待会使用户崩溃……。所以此处我们使用消息队列，保证第一时间响应用户，其他的耗时操作交给消息队列吧。

 1   protected void AddIndex_Click(object sender, EventArgs e)
 2     {
 3         //search. AddIndex();
 4         string Insertstr = "insert into  Article (Title,Contents,Time) values (‘天天就要向上‘,‘天天就要向上‘,‘" + DateTime.Now + "‘) select @@identity ";
 5         int id = Convert.ToInt32((DbHelperSQL.GetSingle(Insertstr)));
 6         China.Model.LuceneIndexArticle ar = new China.Model.LuceneIndexArticle();
 7         ar.ID = id;
 8         ar.Title = "天天就要向上";
 9         ar.Contents = "天天就要向上";
10         ar.AddTime = DateTime.Now.ToString();
11         IndexManage.NewsIndex.IndexAdd(ar);
12     }

 1     /// <Summary>
 2     /// 新增News时，添加新增索引到请求队列
 3     /// </Summary>
 4     /// <param name="artice"></param>
 5     public void IndexAdd(China.Model.LuceneIndexArticle artice)
 6     {
 7         ArticeViewModel addartic = new ArticeViewModel();
 8         addartic.DocId = artice.ID;
 9         addartic.Title = artice.Title; 
10         addartic.HandlerType = IndexType.Insert;
11         addartic.Content = artice.Contents; 
12         newsQueue.Enqueue(addartic);
13     }

2.删除一行数据，删除对应的索引

1     protected void Delete_oneIndex_Click(object sender, EventArgs e)
2     {
3         string delestr = "delete  from Article where ID=" + 1386;
4         DbHelperSQL.ExecuteSql(delestr);
5         IndexManage.NewsIndex.IndexDel(1386);
6     }

 1  /// <Summary>
 2     /// 删除数据时，添加删除请求到消息队列
 3     /// </Summary>
 4     /// <param name="artic"></param>
 5     public void IndexDel(int DocId)
 6     {
 7         ArticeViewModel delartic = new ArticeViewModel();
 8         delartic.OnlyKey = DocId.ToString();
 9         delartic.HandlerType = IndexType.Delete;
10         newsQueue.Enqueue(delartic);
11     }

3.修改索引

1   string upstr = "update News set Title=‘笑嘻嘻笑嘻嘻‘,Content=‘笑嘻嘻笑嘻嘻系‘ where DocId=" + 146475;
2         DbHelperSQL.ExecuteSql(upstr);
3         var wacth = Stopwatch.StartNew();
4         China.Model.LuceneIndexArticle ar = new China.Model.LuceneIndexArticle();
5         ar.ID = 146475;
6         ar.Title = "笑嘻嘻笑嘻嘻";
7         ar.Contents = "笑嘻嘻笑嘻嘻";
8         ar.AddTime = DateTime.Now.ToString();
9         IndexManage.NewsIndex.IndexAdd(ar);

 1  /// <Summary>
 2     /// 对原有所以进行修改
 3     /// </Summary>
 4     /// <param name="artic"></param>
 5     public void IndexModify(China.Model.LuceneIndexArticle artic)
 6     {
 7         ArticeViewModel Modartic = new ArticeViewModel();
 8         Modartic.DocId = artic.ID;
 9         Modartic.Title = artic.Title;  
10         Modartic.Content = artic.Contents; 
11         Modartic.HandlerType = IndexType.Modify;
12         newsQueue.Enqueue(Modartic);
13     }

4.下面我们来看在消息队列中，追加、删除、修改索引的具体操作

 1 FSDirectory directory = FSDirectory.Open(new DirectoryInfo(indexpath), new NativeFSLockFactory());
 2         bool isExsit = IndexReader.IndexExists(directory);
 3         if (isExsit)
 4         {
 5             if (IndexWriter.IsLocked(directory))
 6             {
 7                 IndexWriter.Unlock(directory);
 8             }
 9         }
10         IndexWriter writer = new IndexWriter(directory, PanGuAnalyzer, false);
11         //IndexWriter writer = new IndexWriter(directory, new PanGuAnalyzer(), !isExsit, IndexWriter.MaxFieldLength.LIMITED);
12         while (newsQueue.Count > 0)
13         {
14             Document document = new Document();
15             ArticeViewModel news = newsQueue.Dequeue();
16             if (news.HandlerType == IndexType.Insert)
17             {
18                 document.Add(new Field("ID", news.DocId.ToString(), Field.Store.YES, Field.Index.ANALYZED));
19                 document.Add(new Field("Title", news.Title, Field.Store.YES, Field.Index.ANALYZED));
20                 document.Add(new Field("Contents", news.Content, Field.Store.YES, Field.Index.ANALYZED));
21                 document.Add(new Field("OnlyKey", news.OnlyKey, Field.Store.YES, Field.Index.ANALYZED));
22                 writer.AddDocument(document);
23             }
24             else if (news.HandlerType == IndexType.Delete)
25             {
26                 writer.DeleteDocuments(new Term("OnlyKey", "News1388"));
27             }
28             else if (news.HandlerType == IndexType.Modify)
29             {
30                 //先删除 再新增
31                 writer.DeleteDocuments(new Term("OnlyKey", news.OnlyKey));
32                 document.Add(new Field("OnlyKey", news.OnlyKey, Field.Store.YES, Field.Index.NOT_ANALYZED));
33                 document.Add(new Field("Title", news.Title, Field.Store.YES, Field.Index.ANALYZED,
34                                         Field.TermVector.WITH_POSITIONS_OFFSETS));
35                 document.Add(new Field("Contnets", news.Content, Field.Store.YES, Field.Index.ANALYZED,
36                                         Field.TermVector.WITH_POSITIONS_OFFSETS)); 
37                 writer.AddDocument(document);
38             }
39         }
40         writer.Optimize();
41         writer.Close();
42         directory.Close();