Lucene 简介

package TestLucene;
import java.io.File;
import java.io.FileReader;
import java.io.Reader;
import java.util.Date;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexWriter;
/**
* This class demonstrate the process of creating index with Lucene
* for text files
*/
public class TxtFileIndexer {
public static void main(String[] args) throws Exception{
//indexDir is the directory that hosts Lucene's index files
File   indexDir = new File("D:\\luceneIndex");
//dataDir is the directory that hosts the text files that to be indexed
File   dataDir  = new File("D:\\luceneData");
Analyzer luceneAnalyzer = new StandardAnalyzer();
File[] dataFiles  = dataDir.listFiles();
IndexWriter indexWriter = new IndexWriter(indexDir,luceneAnalyzer,true);
long startTime = new Date().getTime();
for(int i = 0; i < dataFiles.length; i++){
if(dataFiles[i].isFile() && dataFiles[i].getName().endsWith(".txt")){
System.out.println("Indexing file " + dataFiles[i].getCanonicalPath());
Document document = new Document();
Reader txtReader = new FileReader(dataFiles[i]);
document.add(Field.Text("path",dataFiles[i].getCanonicalPath()));
document.add(Field.Text("contents",txtReader));
indexWriter.addDocument(document);
}
}
indexWriter.optimize();
indexWriter.close();
long endTime = new Date().getTime();

System.out.println("It takes " + (endTime - startTime)
+ " milliseconds to create index for the files in directory "
+ dataDir.getPath());
}
}

package TestLucene;
import java.io.File;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.Hits;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.store.FSDirectory;
/**
* This class is used to demonstrate the
* process of searching on an existing
* Lucene index
*
*/
public class TxtFileSearcher {
public static void main(String[] args) throws Exception{
String queryStr = "lucene";
//This is the directory that hosts the Lucene index
File indexDir = new File("D:\\luceneIndex");
FSDirectory directory = FSDirectory.getDirectory(indexDir,false);
IndexSearcher searcher = new IndexSearcher(directory);
if(!indexDir.exists()){
System.out.println("The Lucene index is not exist");
return;
}
Term term = new Term("contents",queryStr.toLowerCase());
TermQuery luceneQuery = new TermQuery(term);
Hits hits = searcher.search(luceneQuery);
for(int i = 0; i < hits.length(); i++){
Document document = hits.doc(i);
System.out.println("File: " + document.get("path"));
}
}
}