Helloworld for Lucene Learning (simple example)

introduction
what's Lucene
Lucene is a function library for information retrieval (Library ), you can add the index and search functions for your application .

LuceneUsers do not need to learn more about full-text search.,Just learn to use a class in the library,You can implement full-text search for your application..

But never think Lucene Is an image Google Such a search engine , Lucene Not even an applicationProgram , It is just a tool , One Library. You can also think of it as an index , A good set of simple and easy-to-use search functions API. Use this set API You can do a lot of searching. , And convenient .

What can Lucene do

Lucene You can index and search any data. . Lucene Regardless of the data source format , As long as it can be converted into text form , You can Lucene Analyzed and utilized . That is to say, whether it is MS word, HTML, PDF Or other forms of files, as long as you can extract text content from them Lucene Used . You can use Lucene Index and search for them .

The above detailed introduction has detailed descriptions in Lucene China. I have also uploaded a copy here. You can also click to download
Paste a simple example belowCode:

Using System;
Using System. configuration;
Using System. Data;
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 System. text;
Using System. IO;

UsingLucene. net. documents;
UsingLucene. net. index;
UsingLucene. net. search;
UsingLucene. net. queryparsers;
UsingLucene. net. analysis. Standard;

Public partial class _ default: system. web. UI. page
{

Protected VoidPage_load (ObjectSender, eventargs E)
{
If(!Ispostback)
Textbox3.text=Server. mappath ("Doc");
}

# Region Create an index
Protected   Void Button2_click ( Object Sender, eventargs E)
{
String Index_store_path = Server. mappath ( " Index " ); // Index_store_path is the index storage directory.
String Index_path = Textbox3.text; // Index_path is the search directory

Indexwriter writer =   Null ;

Writer= NewIndexwriter (index_store_path,NewStandardanalyzer (),True);

Indexdirectory (writer,NewFileinfo (index_path ));
Writer. Optimize ();
Writer. Close ();

Textbox1.text= "Tip: Index completed \ n";
}

Public   Void Indexdirectory (indexwriter writer, fileinfo file)
{
If (Directory. exists (file. fullname ))
{
String [] files = Directory. getfilesystementries (file. fullname );
If (Files ! =   Null )
{
For ( Int I =   0 ; I < Files. length; I ++ )
{
Indexdirectory (writer, New Fileinfo (files [I]); // Here is a recursion
}
}
}
Else   If (File. Extension =   " . Txt " )
{
Indexfile (file, writer );
}
}
Private   Void Indexfile (fileinfo file, indexwriter writer)
{
Document Doc =   New Document ();

Doc. Add (NewField ("Filename", File. fullname, field. Store. Yes, field. Index. un_tokenized ));

Doc. Add (NewField ("Contents",NewStreamreader (file. fullname, system. Text. encoding. Default )));

Writer. adddocument (DOC );
}

# Endregion

# Region Search
Protected   Void Button#click ( Object Sender, eventargs E)
{
String Index_store_path = Server. mappath ( " Index " ); // Index_store_path is the index storage directory.
String Keyword = Textbox2.text; // Search keywords
Indexsearcher searcher;

Searcher= NewIndexsearcher (index_store_path );

Queryparser Q= NewQueryparser ("Contents",NewStandardanalyzer ());

Query=Q. parse (keyword );

Hits hits=Searcher. Search (query );

Textbox1.text= "The search result is" +Hits. Length ()+ "\ N";

If (Hits ! =   Null )
{
For ( Int I =   0 ; I < Hits. Length (); I ++ )
{
Document Doc = Hits. DOC (I );
Textbox1.text = Textbox1.text +   " The "   + (I +   1 ) +   " Search results, file path: "   + Doc. Get ( " Filename " ) +   " \ N " ;
}
}

Searcher. Close ();
}

# Endregion

}

Download the sample code: Click Here (vs. net2008)
Lucene.net version 2.0.0.4, which can be downloaded on Lucene's website: http://incubator.apache.org/lucene.net/
As of today, Lucene's Java version is 2.3 and. Net version is 2.0.