lucene入门代码三（near-real-time）

一个简单的接近实时搜索的例子源自(Lucene in  aiction)

package com.yale.lucene;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.Version;

/**
 * 
 * 接近实时搜索
 * 
 */
public class NearRealTimeTest
{
	public static void main(String[] args) throws Exception
	{
		// Create RAMDirectory
		Directory dir = new RAMDirectory();
		IndexWriter writer = new IndexWriter(dir, new StandardAnalyzer(
				Version.LUCENE_30), IndexWriter.MaxFieldLength.UNLIMITED);
		for(int i =0;i<10;i++){
			Document doc = new Document();
			doc.add(new Field("id",""+i,Field.Store.NO,Field.Index.NOT_ANALYZED_NO_NORMS));
			doc.add(new Field("text","aaa",Field.Store.NO,Field.Index.ANALYZED));
			writer.addDocument(doc);
		}
		//Create near-real-time reader
		IndexReader reader = writer.getReader();
		//Warp reader in  IndexSearcher
		IndexSearcher searcher = new IndexSearcher(reader);
		
		Query query = new TermQuery(new Term("text","aaa"));
		
		TopDocs docs = searcher.search(query,1);
		//Search returns 10 hits
		System.out.println("匹配结果："+docs.totalHits+"次");
		//delete 1 document
		writer.deleteDocuments(new Term("id","7"));
		//add 1 document
		Document doc = new Document();
		doc.add(new Field("id","11",Field.Store.NO,Field.Index.NOT_ANALYZED_NO_NORMS));
		doc.add(new Field("text","bbb",Field.Store.NO,Field.Index.ANALYZED));
		writer.addDocument(doc);
		//Reopen reader
		IndexReader newReader = reader.reopen(); 
		//Confirm reader is new
		System.out.println(reader==newReader);
		reader.close();
		searcher = new IndexSearcher(newReader);
		TopDocs hits = searcher.search(query,10);
		//Search returns 9 hits
		System.out.println("匹配结果："+hits.totalHits+"次");
		query = new TermQuery(new Term("text", "bbb"));
		hits = searcher.search(query, 1);
		//Search returns 1 hits
		System.out.println("匹配结果："+hits.totalHits+"次");
		newReader.close();
		writer.close();
		
	}
}