| /* |
| * 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. |
| */ |
| package org.apache.lucene.analysis.el; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| import org.apache.lucene.analysis.Analyzer; |
| import org.apache.lucene.analysis.CharArraySet; |
| import org.apache.lucene.analysis.StopFilter; |
| import org.apache.lucene.analysis.StopwordAnalyzerBase; |
| import org.apache.lucene.analysis.TokenStream; |
| import org.apache.lucene.analysis.Tokenizer; |
| import org.apache.lucene.analysis.standard.StandardAnalyzer; |
| import org.apache.lucene.analysis.standard.StandardTokenizer; |
| |
| /** |
| * {@link Analyzer} for the Greek language. |
| * |
| * <p>Supports an external list of stopwords (words that will not be indexed at all). A default set |
| * of stopwords is used unless an alternative list is specified. |
| * |
| * <p><b>NOTE</b>: This class uses the same {@link org.apache.lucene.util.Version} dependent |
| * settings as {@link StandardAnalyzer}. |
| * |
| * @since 3.1 |
| */ |
| public final class GreekAnalyzer extends StopwordAnalyzerBase { |
| /** File containing default Greek stopwords. */ |
| public static final String DEFAULT_STOPWORD_FILE = "stopwords.txt"; |
| |
| /** |
| * Returns a set of default Greek-stopwords |
| * |
| * @return a set of default Greek-stopwords |
| */ |
| public static final CharArraySet getDefaultStopSet() { |
| return DefaultSetHolder.DEFAULT_SET; |
| } |
| |
| private static class DefaultSetHolder { |
| private static final CharArraySet DEFAULT_SET; |
| |
| static { |
| try { |
| DEFAULT_SET = loadStopwordSet(false, GreekAnalyzer.class, DEFAULT_STOPWORD_FILE, "#"); |
| } catch (IOException ex) { |
| // default set should always be present as it is part of the |
| // distribution (JAR) |
| throw new RuntimeException("Unable to load default stopword set"); |
| } |
| } |
| } |
| |
| /** Builds an analyzer with the default stop words. */ |
| public GreekAnalyzer() { |
| this(DefaultSetHolder.DEFAULT_SET); |
| } |
| |
| /** |
| * Builds an analyzer with the given stop words. |
| * |
| * <p><b>NOTE:</b> The stopwords set should be pre-processed with the logic of {@link |
| * GreekLowerCaseFilter} for best results. |
| * |
| * @param stopwords a stopword set |
| */ |
| public GreekAnalyzer(CharArraySet stopwords) { |
| super(stopwords); |
| } |
| |
| /** |
| * Creates {@link org.apache.lucene.analysis.Analyzer.TokenStreamComponents} used to tokenize all |
| * the text in the provided {@link Reader}. |
| * |
| * @return {@link org.apache.lucene.analysis.Analyzer.TokenStreamComponents} built from a {@link |
| * StandardTokenizer} filtered with {@link GreekLowerCaseFilter}, {@link StopFilter}, and |
| * {@link GreekStemFilter} |
| */ |
| @Override |
| protected TokenStreamComponents createComponents(String fieldName) { |
| final Tokenizer source = new StandardTokenizer(); |
| TokenStream result = new GreekLowerCaseFilter(source); |
| result = new StopFilter(result, stopwords); |
| result = new GreekStemFilter(result); |
| return new TokenStreamComponents(source, result); |
| } |
| |
| @Override |
| protected TokenStream normalize(String fieldName, TokenStream in) { |
| return new GreekLowerCaseFilter(in); |
| } |
| } |