Lucene全文检索之HelloWorld

Lucene全文检索之HelloWorld
1.下载Lucene4.4 然后解压
2.新建一个Java项目，名称为HelloLucene
3.新建一个lib文件夹，将需要的jar文件复制到lib中，本项目所需要的jar文件如下：

[图]

然后将这些jar文件添加到buildPath中
3.新建一个包com.njupt.zhb，新建一个类：HelloLucene.java，代码如下

[java code]

package com.njupt.zhb;import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.IOException;import java.io.InputStreamReader;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.document.LongField;import org.apache.lucene.document.StringField;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.index.Term;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.util.Version;/* *@author: ZhengHaibo   *web:     http://blog.csdn.net/nuptboyzhb *mail:    [e-mail] *2013-7-05  Nanjing,njupt,China */public class HelloLucene {/** * Index all text files under a directory. * String indexPath = "index";//索引保存的路径 * String docsPath = "";//文档保存的路径（待索引） */public void index(String indexPath,String docsPath) {try {// 1.创建DirectoryDirectory dir = FSDirectory.open(new File(indexPath));//保存在硬盘上// 2.创建IndexWriterAnalyzer analyzer = new StandardAnalyzer(Version.LUCENE_44);IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_44,analyzer);iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);// 设置创建或追加模式IndexWriter writer = new IndexWriter(dir, iwc);final File docDir = new File(docsPath);indexDocs(writer, docDir);writer.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}    public void indexDocs(IndexWriter writer, File file) throws IOException {if (file.canRead()) {if (file.isDirectory()) {//如果是文件夹，则遍历文件夹内的所有文件String[] files = file.list();// an IO error could occurif (files != null) {for (int i = 0; i < files.length; i++) {indexDocs(writer, new File(file, files[i]));}}} else {//如果是文件FileInputStream fis;try {fis = new FileInputStream(file);} catch (FileNotFoundException fnfe) {return;}try {// 3.创建Document对象Document doc = new Document();// 4.为Document添加Field// Add the path of the file as a field named "path". Use a// field that is indexed (i.e. searchable), but don't// tokenize// the field into separate words and don't index term// frequency// or positional information://以文件的文件路径建立FieldField pathField = new StringField("path", file.getPath(),Field.Store.YES);doc.add(pathField);//添加到文档中//以文件的名称建立索引域doc.add( new StringField("filename", file.getName(),Field.Store.YES));//添加到文档中// Add the last modified date of the file a field named// "modified".// Use a LongField that is indexed (i.e. efficiently// filterable with// NumericRangeFilter). This indexes to milli-second// resolution, which// is often too fine. You could instead create a number// based on// year/month/day/hour/minutes/seconds, down the resolution// you require.// For example the long value 2011021714 would mean// February 17, 2011, 2-3 PM.doc.add(new LongField("modified", file.lastModified(),Field.Store.YES));// Add the contents of the file to a field named "contents".// Specify a Reader,// so that the text of the file is tokenized and indexed,// but not stored.// Note that FileReader expects the file to be in UTF-8// encoding.// If that's not the case searching for special characters// will fail.//以文件的内容建立索引域（Field）doc.add(new TextField("contents", new BufferedReader(new InputStreamReader(fis, "UTF-8"))));if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {// New index, so we just add the document (no old// document can be there):System.out.println("adding " + file);writer.addDocument(doc);//将文档写入到索引中（以创建的方式）} else {// Existing index (an old copy of this document may have// been indexed) so// we use updateDocument instead to replace the old one// matching the exact// path, if present:System.out.println("updating " + file);writer.updateDocument(new Term("path", file.getPath()),doc);//以追加方式写入到索引中}} finally {fis.close();}}}}/** * 搜索 * http://blog.csdn.net/nuptboyzhb */public void searcher(String indexPath){try {IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(indexPath)));IndexSearcher searcher = new IndexSearcher(reader);Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_44);String field = "contents";//搜索域是：文档的内容QueryParser parser = new QueryParser(Version.LUCENE_44, field, analyzer);    Query query= parser.parse("南京");//搜索内容中含有“南京”的文档    TopDocs tds=searcher.search(query, 10);//搜索前十个    ScoreDoc[] sds= tds.scoreDocs;    for (ScoreDoc sd:sds) {//将内容中含有“南京”关键字的文档遍历一遍Document document=searcher.doc(sd.doc);System.out.println("score:"+sd.score+"--filename:"+document.get("filename")+"--path:"+document.get("path")+"--time"+document.get("modified"));//打印检索结果中文档的路径}    reader.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}catch (ParseException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

4.为了实验，我在D盘下新建了一个文件夹lucene，里面有三个文件，它们的内容如下：
lucene1.txt
 

Nanjing University Of Posts & Telec

lucene2.txt

南京邮电大学北京市海淀区上海市南京路

lucene3. txt

 2014南京青奥会

5.新建一个Junit测试类，对index函数和searcher函数进行测试，代码如下：

[java code]

package com.njupt.zhb;import org.junit.Test;/* *@author: ZhengHaibo   *web:     http://blog.csdn.net/nuptboyzhb *mail:    [e-mail] *2013-7-05  Nanjing,njupt,China */public class TestJunit {   @Test   public void TestIndex(){   HelloLucene hLucene=new HelloLucene();   hLucene.index("index", "D:\\lucene");   }   @Test   public void TestSearcher(){   HelloLucene hLucene=new HelloLucene();   hLucene.searcher("index");   }}

以Junit方式运行TestIndex函数，运行结果如下：
updating D:\lucene\lucene1.txt
updating D:\lucene\lucene2.txt
updating D:\lucene\lucene3.txt
索引建立完成！
在项目目录的index目录下，就生成了如下索引文件：

[图]

6.搜索，测试TestSearcher函数，运行结果如下：

score:0.53033006--filename:lucene3.txt--path:D:\lucene\lucene3.txt--time1376828819375score:0.48666292--filename:lucene2.txt--path:D:\lucene\lucene2.txt--time1376828783791

可以看出，我们这里只是把分数打印出来了，并没有排名，分数越小，说明越相似！
源代码下载：http://download.csdn.net/detail/nuptboyzhb/5971331

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