Java – Lucene Search Multi Reader

This is a example lucene search multireader index, index structure as below:

–/home/index/

—-index1

—-index2

—-index3

source  lucene search

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

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.MultiReader;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.IndexSearcher;
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;

public class ReadMultiReader {
   public static String directori = "/home/index/";

   public void searchindexreader() throws CorruptIndexException, IOException, ParseException
   {
      //lucene
      File LUCENE_INDEX_DIRECTORY1 = new File(directori+"index1");
      File LUCENE_INDEX_DIRECTORY2 = new File(directori+"index2");
      File LUCENE_INDEX_DIRECTORY3 = new File(directori+"index3");
      String search = "content:bagus";
      System.out.println("Searching for: "+search);

      IndexReader iR1 = IndexReader.open(FSDirectory.open(LUCENE_INDEX_DIRECTORY1));
      IndexReader iR2 = IndexReader.open(FSDirectory.open(LUCENE_INDEX_DIRECTORY2));
      IndexReader iR3 = IndexReader.open(FSDirectory.open(LUCENE_INDEX_DIRECTORY3));

      Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT);

      MultiReader mr = new MultiReader(iR1,iR2,iR3);
      IndexSearcher indexSearcher = new IndexSearcher(mr);

      QueryParser queryParser = new QueryParser(Version.LUCENE_CURRENT,"content", analyzer);
      org.apache.lucene.search.Query query = queryParser.parse(search);
      TopDocs topDocs = indexSearcher.search(query, null, 5);

      ScoreDoc[] scoreDosArray = topDocs.scoreDocs;
      System.out.println(topDocs.totalHits);
      Integer j=1;
      for(ScoreDoc scoredoc: scoreDosArray){
         //Retrieve the matched document and show relevant details
         Document doc = indexSearcher.doc(scoredoc.doc);
         System.out.println(j+" "+doc.get("content"));
         System.out.println("");
         j++;
      }
   }

   public static void main(String[] args) throws Exception {
      ReadMultiReader run = new ReadMultiReader();
      run.searchindexreader();
   }
}