Lucene学习之构建简单的文档库

在构建一个简单的文档库时，需要两个条件，第一，必须能抓取文档的内容，第二，根据抓取的内容构建文档库的索引，然后根据进行搜索。前面两篇博客中介绍的tika和Lucene可以分别满足这两个条件，本篇博客，就结合这两个框架来创建一个简单的文档库，在介绍Lucene入门时，我们使用了FileReader来读入字符文件，在这里我们就要使用tike来读入并解析各种文档了。我们只需要在Lucene入门时所使用的代码中，修改一行代码即可，为了便于大家运行和调试，将全部代码贴出，修改的代码在140行：

 

package com.hsdl.lucene;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.CorruptIndexException;
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.ParseException;
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.store.LockObtainFailedException;
import org.apache.lucene.util.Version;
import org.apache.tika.Tika;
import org.wltea.analyzer.lucene.IKAnalyzer;

public class LuceneDemo2 {
	private static String contentFieldName = "content";
	private static Tika tika = new Tika();
	public static void main(String[] args) {
//		Analyzer analyzer = new IKAnalyzer();
		Analyzer analyzer = new IKAnalyzer();
		try {
			String docPath = "D:/work/lucene/tika/doc";
			String indexPath = "D:/work/lucene/tika/index";
			//创建索引
			createIndex(analyzer, indexPath, docPath);
			//搜索
			search(analyzer, indexPath, "微信");
		} catch (CorruptIndexException e) {
			e.printStackTrace();
		} catch (LockObtainFailedException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} 
	}

	/**
	 * 创建索引
	 * 
	 * @param analyzer
	 * @param indexPath
	 * @param docPath
	 * @throws IOException
	 * @throws CorruptIndexException
	 * @throws LockObtainFailedException
	 */
	private static void createIndex(Analyzer analyzer, String indexPath,
			String docPath) throws IOException, CorruptIndexException,
			LockObtainFailedException {
		IndexWriter iwriter;
		Directory directory = FSDirectory.open(new File(indexPath));
		// 配置IndexWriterConfig
		IndexWriterConfig iwConfig = new IndexWriterConfig(Version.LUCENE_45,
				analyzer);
		iwConfig.setOpenMode(OpenMode.CREATE_OR_APPEND);
		iwriter = new IndexWriter(directory, iwConfig);
		File file = new File(docPath);
		indexDocs(iwriter, file);
		iwriter.close();
	}

	/**
	 * 搜索
	 * 
	 * @param analyzer
	 * @param indexPath
	 * @param queryStr
	 * @throws CorruptIndexException
	 * @throws IOException
	 * @throws ParseException
	 */
	private static void search(Analyzer analyzer, String indexPath,
			String queryStr) throws CorruptIndexException, IOException,
			ParseException {
		Directory directory = FSDirectory.open(new File(indexPath));
		// 搜索过程**********************************
		// 实例化搜索器
		IndexReader ireader = DirectoryReader.open(directory);
		IndexSearcher isearcher = new IndexSearcher(ireader);

		// 使用QueryParser查询分析器构造Query对象
		QueryParser qp = new QueryParser(Version.LUCENE_45, contentFieldName, analyzer);
		qp.setDefaultOperator(QueryParser.AND_OPERATOR);
		Query query = qp.parse(queryStr);

		// 搜索相似度最高的10条记录
		TopDocs topDocs = isearcher.search(query, 10);
		System.out.println("命中：" + topDocs.totalHits);
		// 输出结果
		ScoreDoc[] scoreDocs = topDocs.scoreDocs;
		System.out.println(scoreDocs.length);
		for (int i = 0; i < scoreDocs.length; i++) {
			Document targetDoc = isearcher.doc(scoreDocs[i].doc);
			System.out.println("内容：" + targetDoc.toString());
			System.out.println(targetDoc.get("fileName") + "["
					+ targetDoc.get("path") + "]");
		}
	}
	/**
	 * 根据指定存放内容的文件或目录创建索引
	 * @param iwriter
	 * @param file
	 * @throws IOException
	 */
	public static void indexDocs(IndexWriter iwriter, File file) throws IOException {
		if (file.canRead())
			if (file.isDirectory()) {
				String[] files = file.list();

				if (files != null)
					for (int i = 0; i < files.length; i++)
						indexDocs(iwriter, new File(file, files[i]));
			} else {
				Document doc = null;
				FileInputStream fis=null;
				try {
					doc = new Document();
					doc.add(new StringField("ID", "10000", Field.Store.YES));
					fis = new FileInputStream(file);
					//此处添加文件内容时，需要根据tika获取Reader对象
					doc.add(new TextField(contentFieldName, tika.parse(file)));
					doc.add(new StringField("fileName", file.getName(),
							Field.Store.YES));
					doc.add(new StringField("path", file.getAbsolutePath(),
							Field.Store.YES));
					iwriter.addDocument(doc);
				} finally {
					if(fis!=null){
						fis.close();
					}
				}
			}
	}
}