com.fdt.sdl.core.analyzer.phonetix.lucene.PhoneticAnalyzer.java Source code

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Here is the source code for com.fdt.sdl.core.analyzer.phonetix.lucene.PhoneticAnalyzer.java

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/*
Phonetix for Lucene: phonetic algorithms for the Lucene search-engine.
Copyright (C) 2001-2003  Claus Engel
    
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
    
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.
    
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
package com.fdt.sdl.core.analyzer.phonetix.lucene;

import java.io.Reader;
import java.util.Set;

import com.fdt.sdl.core.analyzer.phonetix.PhoneticEncoder;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.LowerCaseFilter;
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;

/**
 * Filters {@link StandardTokenizer} with {@link StandardFilter},
 * {@link LowerCaseFilter}, {@link StopFilter}, and {@link PhoneticFilter}.
 * <br><br>
 * To use a <tt>PhoneticAnalyzer</tt>, simply build it with a
 * {@link PhoneticEncoder} and use it to create and search indices
 * of Lucene.
 *
 * @see com.tangentum.phonetix.Soundex
 * @see com.tangentum.phonetix.Metaphone
 * @see com.tangentum.phonetix.DoubleMetaphone
 * @author Claus Engel
 */
public class PhoneticAnalyzer extends Analyzer {
    protected final PhoneticEncoder encoder;
    protected final Set stopTable;

    /**
     * An array containing some common words that are not usually useful for searching.
     */
    private static final String[] STOP_WORDS = { "a", "and", "are", "as", "at", "be", "but", "by", "for", "if",
            "in", "into", "is", "it", "no", "not", "of", "on", "or", "s", "such", "t", "that", "the", "their",
            "then", "there", "these", "they", "this", "to", "was", "will", "with" };

    /**
     * Builds an analyzer with the given phonetic encoder.
     */
    public PhoneticAnalyzer(final PhoneticEncoder phoneticEncoder) {
        encoder = phoneticEncoder;
        stopTable = StopFilter.makeStopSet(STOP_WORDS);
    }

    /**
     * Builds an analyzer with the given phonetic encoder
     * and the given stop words.
     */
    public PhoneticAnalyzer(final PhoneticEncoder phoneticEncoder, final String[] stopWords) {
        encoder = phoneticEncoder;
        stopTable = StopFilter.makeStopSet(stopWords);
    }

    /**
     * Returns the phonetic encoder.
     */
    public final PhoneticEncoder encoder() {
        return encoder;
    }

    /**
     * Constructs a {@link StandardTokenizer} filtered by a {@link
     * StandardFilter}, a {@link LowerCaseFilter}, a {@link StopFilter},
     * and a {@link PhoneticFilter}.
     */
    public TokenStream tokenStream(String fieldname, final Reader reader) {
        TokenStream result = new StandardTokenizer(reader);
        result = new StandardFilter(result);
        result = new LowerCaseFilter(result);
        result = new StopFilter(result, stopTable);
        result = new PhoneticFilter(result, encoder);
        return result;
    }

}