SynLookup.java :  » Net » lucene-connector » org » apache » lucene » wordnet » Java Open Source

package org.apache.lucene.wordnet;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.store.*;
import org.apache.lucene.search.*;
import org.apache.lucene.index.*;
import org.apache.lucene.document.*;
import org.apache.lucene.analysis.*;
import java.io.*;
import java.util.*;


/**
 * Test program to look up synonyms.
 */
public class SynLookup {

  public static void main(String[] args) throws IOException {
    if (args.length != 2) {
      System.out.println(
                 "java org.apache.lucene.wordnet.SynLookup <index path> <word>");
    }

    FSDirectory directory = FSDirectory.getDirectory(args[0], false);
    IndexSearcher searcher = new IndexSearcher(directory);

    String word = args[1];
    Hits hits = searcher.search(
                  new TermQuery(new Term(Syns2Index.F_WORD, word)));

    if (hits.length() == 0) {
      System.out.println("No synonyms found for " + word);
    } else {
      System.out.println("Synonyms found for \"" + word + "\":");
    }

    for (int i = 0; i < hits.length(); i++) {
      Document doc = hits.doc(i);

      String[] values = doc.getValues(Syns2Index.F_SYN);

      for (int j = 0; j < values.length; j++) {
        System.out.println(values[j]);
      }
    }

    searcher.close();
    directory.close();
  }


  /**
   * Perform synonym expansion on a query.
   *
   * @param query
   * @param syns
   * @param a
   * @param field
   * @param boost
   */ 
  public static Query expand( String query,
                Searcher syns,
                Analyzer a,
                String field,
                float boost)
    throws IOException
  {
    Set already = new HashSet(); // avoid dups    
    List top = new LinkedList(); // needs to be separately listed..

    // [1] Parse query into separate words so that when we expand we can avoid dups
    TokenStream ts = a.tokenStream( field, new StringReader( query));
    org.apache.lucene.analysis.Token t;
    while ( (t = ts.next()) != null)
    {
      String word = t.termText();
      if ( already.add( word))
        top.add( word);
    }
    BooleanQuery tmp = new BooleanQuery();
    
    // [2] form query
    Iterator it = top.iterator();
    while ( it.hasNext())
    {
      // [2a] add to level words in
      String word = (String) it.next();
      TermQuery tq = new TermQuery( new Term( field, word));
      tmp.add( tq, BooleanClause.Occur.SHOULD);

      // [2b] add in unique synonums
      Hits hits = syns.search( new TermQuery( new Term(Syns2Index.F_WORD, word)));
      for (int i = 0; i < hits.length(); i++)
      {
        Document doc = hits.doc(i);
        String[] values = doc.getValues( Syns2Index.F_SYN);
        for ( int j = 0; j < values.length; j++)
        {
          String syn = values[ j];
          if ( already.add( syn))
          {
            tq = new TermQuery( new Term( field, syn));
            if ( boost > 0) // else keep normal 1.0
              tq.setBoost( boost);
            tmp.add( tq, BooleanClause.Occur.SHOULD); 
          }
        }
      }
    }


    return tmp;
  }
                
}