lucene学习01之简单小例子初步认识lucene

        lucene是干嘛用的，这里不多说。这些写个简单例子，简单对lucene的使用有个初步了解。

LuceneFileHelper.java

package com.fei;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.IndexWriterConfig.OpenMode;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;

public class LuceneFileHelper {

	private final static String FIELD_CONTENT = "content";
	private final static String FIELD_FILEPATH = "filePath";
	private final static String FIELD_FILENAME = "fileName";
	
	/**
	 * 创建索引
	 * @param sourceFilePath
	 * @param indexFileDir
	 */
	public static void createIndex(File sourceFile,String indexFileDir){
		Directory directory = null;
		IndexWriter indexWriter = null;
		try {
			//1.创建Directory
			directory = FSDirectory.open(new File(indexFileDir));
			//2.创建IndexWriter
			IndexWriterConfig indexWriterConf = new IndexWriterConfig(Version.LUCENE_4_9,new StandardAnalyzer(Version.LUCENE_4_9));
			indexWriter = new IndexWriter(directory,indexWriterConf);
			//3.创建Document
			Document document = new Document();
			document.add(new TextField(FIELD_CONTENT,new FileReader(sourceFile)));
			document.add(new TextField(FIELD_FILENAME,sourceFile.getName(),Field.Store.YES));
			document.add(new TextField(FIELD_FILEPATH,sourceFile.getAbsolutePath(),Field.Store.YES));
			//4.把Document写到索引中
			indexWriter.addDocument(document);
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			if(indexWriter != null){
				try {
					indexWriter.close();
				} catch (IOException e) {
					indexWriter = null;
				}
			}
		}
	}
	/**
	 * 在指定的索引目录下搜索指定的内容，并返回指定内容所在的文件名
	 * @param searcherContent
	 * @param indexDir
	 * @return
	 */
	public static List<String> searcher(String searcherContent, String indexDir){
		List<String> filePaths = new ArrayList<String>();
		try {
			//1.创建Directory
			Directory directory = FSDirectory.open(new File(indexDir));
			//2.创建IndexReader
			IndexReader indexReader = DirectoryReader.open(directory);
			//3.根据IndexReader创建IndexSearcher
			IndexSearcher indexSearcher = new IndexSearcher(indexReader);
			//4.创建搜索的Query
			//先创建QueryParser,确定要搜索文档中的field
			QueryParser parser = new QueryParser(Version.LUCENE_4_9,FIELD_CONTENT,new StandardAnalyzer(Version.LUCENE_4_9));
			//指定要搜索的内容
			Query query = parser.parse(searcherContent);
			//5.根据IndexSearcher搜索并返回TopDocs
			TopDocs topDocs = indexSearcher.search(query, 10);//最多返回10个
			//6.根据TopDocs获取ScoreDoc[]对象
			ScoreDoc[] scoreDocs = topDocs.scoreDocs;
			for(ScoreDoc sd : scoreDocs){
				Document document = indexSearcher.doc(sd.doc);
				filePaths.add(document.get(FIELD_FILEPATH));
			}
			
			indexReader.close();
		} catch (Exception e) {
			
			e.printStackTrace();
		}
		
		return filePaths;
	}
}

  这里使用的 lucene的版本是4.9的，不同的版本，创建某些对象时，方法有可能有一些差别，具体的用法，可以下载对应版本的源码来看看里面自带的demo。

LuceneFileHelperTest.java

package lucene001;

import java.io.File;
import java.util.List;

import org.junit.Test;

import com.fei.LuceneFileHelper;

public class LuceneFileHelperTest {

	@Test
	public void indexTest(){
		String sourceFileDir = "E:\\lucene\\source";
		String indexFileDir = "E:\\lucene\\index";
		
		for(File file : new File(sourceFileDir).listFiles()){
			LuceneFileHelper.createIndex(file, indexFileDir);
		}
	}
	@Test
	public void searcherTest(){
		String indexFileDir = "E:\\lucene\\index";
		List<String> filePaths = LuceneFileHelper.searcher("lucene", indexFileDir);
		System.out.println("========含有\"lucene\"的文件===========");
		System.out.println(filePaths.toString());
		
		
		filePaths = LuceneFileHelper.searcher("hello", indexFileDir);
		System.out.println("========含有\"hello\"的文件===========");
		System.out.println(filePaths.toString());
	}
}

   建立文件夹e:\\lucene\\source 及e:\\lucene\\index，前者放一些测试文件，后者放lucene根据测试文件生成的索引文件，在e:\\lucene\\source下创建a.txt,内容写上:hello java,b.txt写上:hello lucene.

   写运行测试类LuceneFileHelperTest.java中的indexTest()方法，运行后，看到e:\\lucene\\index下生成了一些文件.

    运行测试类LuceneFileHelperTest.java中的searcherTest()方法，控制台中，会看到：