com.sxc.lucene.analysis.synonym.WordNetSynonymEngine.java Source code

Introduction

Here is the source code for com.sxc.lucene.analysis.synonym.WordNetSynonymEngine.java

Source

package com.sxc.lucene.analysis.synonym;

/**
 * Copyright Manning Publications Co.
 *
 * Licensed 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 lan      
*/

import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.Directory;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Iterator;

import lia.common.AllDocCollector;

// From chapter 9
public class WordNetSynonymEngine implements SynonymEngine {
    IndexSearcher searcher;
    Directory fsDir;

    public WordNetSynonymEngine(File index) throws IOException {
        fsDir = FSDirectory.open(index);
        searcher = new IndexSearcher(DirectoryReader.open(fsDir));
    }

    public void close() throws IOException {
        searcher.getIndexReader().close();
        fsDir.close();
    }

    public String[] getSynonyms(String word) throws IOException {

        List<String> synList = new ArrayList<String>();

        AllDocCollector collector = new AllDocCollector(); // #A

        searcher.search(new TermQuery(new Term("word", word)), collector);

        for (ScoreDoc hit : collector.getHits()) { // #B
            Document doc = searcher.doc(hit.doc);

            String[] values = doc.getValues("syn");

            for (String syn : values) { // #C
                synList.add(syn);
            }
        }

        return synList.toArray(new String[0]);
    }
}

/*
  #A Collect every matching document
  #B Iterate over matching documents
  #C Record synonyms
*/