apache lucene 一个最简单的实例

就像每个程序都有一个Hello World来让人体验它一样，lucene也可以很简单的提供一个实例。如下（来自lucene in action的例子）有两个类组成：

一个是建立索引

package my;

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;

package my;

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 {

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]);

String q = args[1];

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

throw new Exception(indexDir

+ " does not exist or is not a directory.");

}

search(indexDir, q);

}

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

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

IndexSearcher is = new IndexSearcher(fsDir);

Query query = QueryParser.parse(q, "contents", new StandardAnalyzer());

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

Hits hits = is.search(query);

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);

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

}

}

}

ok，这样就简单实现了，在搜索目录下所有txt，找出包括某一个字符串的txt文件名的功能。

下篇文章将介绍一下lucene的核心类