lucene+nutch学习笔记五：创建一个简单的索引

package chapter5;

import java.io.IOException;
import java.util.Date;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.SimpleAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexCommitPoint;

import org.apache.lucene.store.LockObtainFailedException;

public class LuceneIndexTest {

	/**
	 * @param args
	 */
	private static String dest_Index_Path = "D:\\workshop\\TextIndex";
	static protected String[] keywords = { "001", "002", "003" };
	static protected String[] textdetail = { "记录一", "记录二", "记录三" };

	public static void main(String[] args) {
		Date start = new Date();
		Analyzer 


textAnalyzer = new SimpleAnalyzer();
		try {
			IndexWriter 


textIndex = new IndexWriter(dest_Index_Path,
					textAnalyzer, true);//true or false menus create or update
			for (int i = 0; i < 3; i++) {
				Document 

document = new Document();
				Field 

field_id = new Field("id", keywords[i], Field.Store.YES,
						
Field.Index.UN_TOKENIZED

);
				document.add(field_id);
				Field field_content = new Field("content", textdetail[i],
						Field.Store.YES, Field.Index.TOKENIZED

);
				document.add(field_content);

			}
			textIndex.optimize();// 不关闭索引只保存在内存里面。
			
textIndex.close();


			Date end = new Date();
			long index_tm = end.getTime() - start.getTime();
			System.out.println("Total Time :(ms)");
			System.out.println(index_tm);

		} catch (CorruptIndexException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (LockObtainFailedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.println("Index Success!");

	}

}

 注意，测试代码的版本是lucene2.3.jar

A

IndexWriter 

textIndex = new IndexWriter(dest_Index_Path,
					textAnalyzer, true);//true or false menus create or update

表示的是索引创建器，3个参数是，路径，分析器，是否重建。第3个参数为true，表示重新建立索引（假若存在则删除原文件），假若为false，那么在原来的基础上更改，这就是创建增量索引。

还有一个构造函数参数是一个目录，可以用以下方法取得。

            Directory dir=FSDirectory.getDirectory(dir_name);
            Analyzer textAnalyzer=new StandardAnalyzer();
            IndexWriter indexWriter=new IndexWriter(dir,textAnalyzer,false);

B Analyzer textAnalyzer = new SimpleAnalyzer();

Analyzer是索引分析器，每个域的数据在添加时都会使用它来进行分析。

 

C

 

Document 

document = new Document();
				Field 

field_id = new Field("id", keywords[i], Field.Store.YES,
						
Field.Index.UN_TOKENIZED

);

 

这里的Document并不是真正意识的文档，而是一个抽象的概念，可以理解为一个要被索引的内容的一个容器，有不同的Field组成的Document .

 

 D 另外就是索引管理器IndexReader ,用来管理索引的强大工具。可以用它来删除索引

	File indexDir=new File("D:\\workshop\\TextIndex");
		try {
			IndexReader indexReader=IndexReader.open(indexDir);

//准备索引文件的目录，生成对象读取索引内容
			Term term=new Term("name","xx.txt");//创建要删除的对象的索引项的表示（Term）


			indexReader.deleteDocuments

(term);//删除符合索引项的文档
			indexReader.close

();//关闭，实现物力删除
		} catch (CorruptIndexException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

 下面贴一个给文本文件建立索引的代码，一共参考：

package chapter5;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;

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.index.IndexWriter;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;

public class LunceneIndexManager {

	/**
	 * @param args
	 */
	private static String dest_Index_Path = "D:\\workshop\\TextIndex";
	private static String text_File_Path = "D:\\largeData\\xx.txt";
	
	
	public static void main(String[] args) throws IOException {
		
		Date start=new Date();
		File file=new File(text_File_Path);
		
		try {
			FileReader fileReader=new FileReader(file);
			String dir_name=dest_Index_Path;
			
			Directory dir=FSDirectory.getDirectory(dir_name);
			Analyzer textAnalyzer=new StandardAnalyzer();
			IndexWriter indexWriter=new IndexWriter(dir,textAnalyzer,false);
			
			Document document=new Document();
			
			Field field_name=new Field("name",file.getName(),Field.Store.YES,Field.Index.UN_TOKENIZED);
			document.add(field_name);
			
			InputStream inputStream=new FileInputStream(file);
			int leng=inputStream.available();
			byte[] by=new byte[leng];
			inputStream.read(by);
			inputStream.close();
			
			String content=new String(by);
			
			Field field_content=new Field("content",content,Field.Store.YES,Field.Index.TOKENIZED);
			document.add(field_content);
			
			indexWriter.addDocument(document);
			indexWriter.optimize();
			indexWriter.close();
			Date end=new Date();
			long ss=end.getTime()-start.getTime();
			System.out.println("Total Time:(ms)");
			System.out.println(ss);
			
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.println("Index Sucess!");
		

	}

}