/*
* Copyright (c) 2009-2010 Lockheed Martin Corporation
*
* 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 language governing permissions and
* limitations under the License.
*/
package org.eurekastreams.commons.search.analysis;
import java.io.Reader;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.LowerCaseFilter;
import org.apache.lucene.analysis.StopAnalyzer;
import org.apache.lucene.analysis.StopFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;
import org.apache.lucene.index.memory.SynonymTokenFilter;
import org.apache.solr.analysis.EnglishPorterFilterFactory;
/**
* Analyzer that indexes lower-cased stems of the significant words and their
* synonyms in the text.
*/
public class TextSynonymStemmerAnalyzer extends Analyzer
{
/**
* Max number of synonyms to grab.
*/
private static final int MAX_NUMBER_OF_SYNONYMS = 100;
/**
* Tokenize the stream.
*
* @param fieldName
* the name of the field
* @param reader
* the reader
* @return the stream
*/
@Override
public TokenStream tokenStream(final String fieldName, final Reader reader)
{
TokenStream tokenStream = new StandardTokenizer(reader);
TokenStream result = new StandardFilter(tokenStream);
result = new LowerCaseFilter(result);
result = new StopFilter(result, StopAnalyzer.ENGLISH_STOP_WORDS);
result = new SynonymTokenFilter(result, SynonymMapFactory.getSynonymMap(), MAX_NUMBER_OF_SYNONYMS);
result = new EnglishPorterFilterFactory().create(result);
return result;
}
}