通过addIndexes将内存中的索引加入到磁盘索引

package com.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.IndexWriter;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.Hits;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.RAMDirectory;

public class RamAndDiskIndex {

	private static String path = "d:/index";
	public static void main(String[] args) {
		index();
		search();
	}
	
	public static void index(){
		try{
			Directory ramDir = new RAMDirectory();
			Directory diskDir = FSDirectory.getDirectory(path);
			
			IndexWriter ramWriter = new IndexWriter(ramDir,new StandardAnalyzer(),true);
			IndexWriter diskWriter = new IndexWriter(diskDir,new StandardAnalyzer(),true);
			
			
			//新增一条数据到内存索引中，然后再由内存索引加入到磁盘索引中去
			
			Document doc = new Document();
			doc.add(new Field("id","123456",Field.Store.YES,Field.Index.TOKENIZED));
			doc.add(new Field("value","hello world",Field.Store.YES,Field.Index.TOKENIZED));
			//添加到内存
			ramWriter.addDocument(doc);
			//关闭ram的IndexWriter实例,把数据给ramDir, 必须要先关闭，然后才能调用addIndexes方法把ramDir参数传入;
			ramWriter.close();
			//通过disk的IndexWriter实例的addIndexes 
			diskWriter.addIndexes(new Directory[]{ramDir});
			
			diskWriter.close();
		}catch(Exception e){
			e.printStackTrace();
		}
	}
	
	
	public static Query queryParser(){
		
		QueryParser queryParser = new QueryParser("value", new StandardAnalyzer());
		try {
			Query query =  queryParser.parse("world");
			return query;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
	
	public static void search(){
		try {
			IndexSearcher search = new IndexSearcher(path);
			
			Query query = queryParser();
			
			Hits hits = search.search(query);
			if(hits==null)
				return;
			for (int i = 0; i < hits.length(); i++) {
				Document doc = hits.doc(i);
				System.out.println("id = "+hits.id(i));
				System.out.println("");
			}
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}