X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/tr/TurkishAnalyzer.java diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/tr/TurkishAnalyzer.java b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/tr/TurkishAnalyzer.java new file mode 100644 index 0000000..d6a315e --- /dev/null +++ b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/tr/TurkishAnalyzer.java @@ -0,0 +1,134 @@ +package org.apache.lucene.analysis.tr; + +/** + * 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 java.io.IOException; +import java.io.Reader; +import java.util.Set; + +import org.apache.lucene.analysis.Analyzer; +import org.apache.lucene.analysis.CharArraySet; +import org.apache.lucene.analysis.KeywordMarkerFilter; +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.snowball.SnowballFilter; +import org.apache.lucene.analysis.standard.StandardFilter; +import org.apache.lucene.analysis.standard.StandardTokenizer; +import org.apache.lucene.util.Version; +import org.tartarus.snowball.ext.TurkishStemmer; + +/** + * {@link Analyzer} for Turkish. + */ +public final class TurkishAnalyzer extends StopwordAnalyzerBase { + private final Set stemExclusionSet; + + /** File containing default Turkish stopwords. */ + public final static String DEFAULT_STOPWORD_FILE = "stopwords.txt"; + /** + * The comment character in the stopwords file. + * All lines prefixed with this will be ignored. + */ + private static final String STOPWORDS_COMMENT = "#"; + + /** + * Returns an unmodifiable instance of the default stop words set. + * @return default stop words set. + */ + public static Set getDefaultStopSet(){ + return DefaultSetHolder.DEFAULT_STOP_SET; + } + + /** + * Atomically loads the DEFAULT_STOP_SET in a lazy fashion once the outer class + * accesses the static final set the first time.; + */ + private static class DefaultSetHolder { + static final Set DEFAULT_STOP_SET; + + static { + try { + DEFAULT_STOP_SET = loadStopwordSet(false, TurkishAnalyzer.class, + DEFAULT_STOPWORD_FILE, STOPWORDS_COMMENT); + } 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: {@link #DEFAULT_STOPWORD_FILE}. + */ + public TurkishAnalyzer(Version matchVersion) { + this(matchVersion, DefaultSetHolder.DEFAULT_STOP_SET); + } + + /** + * Builds an analyzer with the given stop words. + * + * @param matchVersion lucene compatibility version + * @param stopwords a stopword set + */ + public TurkishAnalyzer(Version matchVersion, Set stopwords) { + this(matchVersion, stopwords, CharArraySet.EMPTY_SET); + } + + /** + * Builds an analyzer with the given stop words. If a non-empty stem exclusion set is + * provided this analyzer will add a {@link KeywordMarkerFilter} before + * stemming. + * + * @param matchVersion lucene compatibility version + * @param stopwords a stopword set + * @param stemExclusionSet a set of terms not to be stemmed + */ + public TurkishAnalyzer(Version matchVersion, Set stopwords, Set stemExclusionSet) { + super(matchVersion, stopwords); + this.stemExclusionSet = CharArraySet.unmodifiableSet(CharArraySet.copy( + matchVersion, stemExclusionSet)); + } + + /** + * Creates a + * {@link org.apache.lucene.analysis.ReusableAnalyzerBase.TokenStreamComponents} + * which tokenizes all the text in the provided {@link Reader}. + * + * @return A + * {@link org.apache.lucene.analysis.ReusableAnalyzerBase.TokenStreamComponents} + * built from an {@link StandardTokenizer} filtered with + * {@link StandardFilter}, {@link TurkishLowerCaseFilter}, + * {@link StopFilter}, {@link KeywordMarkerFilter} if a stem + * exclusion set is provided and {@link SnowballFilter}. + */ + @Override + protected TokenStreamComponents createComponents(String fieldName, + Reader reader) { + final Tokenizer source = new StandardTokenizer(matchVersion, reader); + TokenStream result = new StandardFilter(matchVersion, source); + result = new TurkishLowerCaseFilter(result); + result = new StopFilter(matchVersion, result, stopwords); + if(!stemExclusionSet.isEmpty()) + result = new KeywordMarkerFilter(result, stemExclusionSet); + result = new SnowballFilter(result, new TurkishStemmer()); + return new TokenStreamComponents(source, result); + } +}