Lucene学习笔记（一）-白红宇

建立索引:

import java.io.File;

import java.io.FileReader;

import java.io.IOException;

import java.util.Date;

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;

public class Indexer

{

//建立索引

/**

* @param args

public static void main(String[] args) throws Exception

{

// TODO Auto-generated method stub

if (args.length != 2)

{

throw new Exception("Usage: java" + Indexer.class.getName()+ "<index dir> <data dir>");

}

File indexDir = new File(args[0]);//存放索引的路径

File dataDir = new File(args[1]); //要建立索引的目录路径

long start = new Date().getTime();

int numIndexed = index(indexDir, dataDir); //建立索引

long end = new Date().getTime();

System.out.println("Indexing " + numIndexed + " files took " + (end - start) + " milliseconds");

}

private static int index(File indexDir, File dataDir) throws IOException

{

if (!dataDir.exists() || !dataDir.isDirectory())

{

throw new IOException(dataDir+ " does not exist or is not a directory");

}

IndexWriter writer = new IndexWriter(indexDir, new StandardAnalyzer(), true);

writer.setUseCompoundFile(false);

indexDirectory(writer, dataDir);

int numIndexed = writer.docCount();

writer.optimize();

writer.close();

return numIndexed;

}

private static void indexDirectory(IndexWriter writer, File dataDir) throws IOException

{

// TODO Auto-generated method stub

File[] files = dataDir.listFiles();

for (int i = 0; i < files.length; i++)

{

File f = files[i];

if (f.isDirectory())

{

indexDirectory(writer, f);

}

else if (f.getName().endsWith(".txt"))

{

indexFile(writer, f);

}

private static void indexFile(IndexWriter writer, File f) throws IOException

{

if (f.isHidden() || !f.exists() || !f.canRead())

{

return;

}

System.out.println("Indexing " + f.getCanonicalPath());

Document doc = new Document();

doc.add(new Field("contents", new FileReader(f)));

doc.add(new Field("filename", f.getCanonicalPath(), Field.Store.YES, Field.Index.TOKENIZED));

writer.addDocument(doc);

}

搜索:

import java.io.File;

import java.util.Date;

import org.apache.lucene.analysis.standard.StandardAnalyzer;

import org.apache.lucene.document.Document;

import org.apache.lucene.queryParser.QueryParser;

import org.apache.lucene.search.Hits;

import org.apache.lucene.search.IndexSearcher;

import org.apache.lucene.search.Query;

import org.apache.lucene.store.Directory;

import org.apache.lucene.store.FSDirectory;

public class Searcher

{

/**

* @param args

public static void main(String[] args) throws Exception

{

if (args.length != 2)

{

throw new Exception("Usage: java " + Searcher.class.getName()+ " <index dir> <auery>");

}

File indexDir = new File(args[0]);//要搜索的索引所在目录

String q = args[1]; //搜索关键字

if (!indexDir.exists() || !indexDir.isDirectory())

{

throw new Exception(indexDir + " does not exist or is not a directory.");

}

search(indexDir, q);

}

private static void search(File indexDir, String q) throws Exception

{

Directory fsDir = FSDirectory.getDirectory(indexDir, false);

IndexSearcher is = new IndexSearcher(fsDir);// 打开索引

QueryParser parser = new QueryParser("contents", new StandardAnalyzer());

Query query = parser.parse(q); //对文本内容进行分析查询

long start = new Date().getTime();

Hits hits = is.search(query); //搜索索引

long end = new Date().getTime();

System.err.println("Found " + hits.length() + " document(s) (in " + (end - start) + " milliseconds) that matched query '" + q + "’:");

for (int i = 0; i < hits.length(); i++)

{

Document doc = hits.doc(i); //得到匹配的文档

System.out.println(doc.get("filename"));

}

重点学习的几个方面：

1， Lucene的索引结构，

2，各种异构数据源的解析器（Parser）

3，分词器(Analyzer)提取索引项（尤其是如何进行中文分词）

注：这里使用的是lucene2.2.0

本文转自Phinecos(洞庭散人)博客园博客，原文链接：http://www.cnblogs.com/phinecos/archive/2007/08/25/869654.html，如需转载请自行联系原作者