| package org.apache.lucene.analysis.ru; |
| |
| /* |
| * 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.nio.charset.StandardCharsets; |
| import java.util.Arrays; |
| |
| import org.apache.lucene.analysis.Analyzer; |
| 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.analysis.util.CharArraySet; |
| import org.apache.lucene.analysis.util.StopwordAnalyzerBase; |
| import org.apache.lucene.analysis.util.WordlistLoader; |
| import org.apache.lucene.analysis.core.LowerCaseFilter; |
| import org.apache.lucene.analysis.core.StopFilter; |
| import org.apache.lucene.analysis.miscellaneous.SetKeywordMarkerFilter; |
| import org.apache.lucene.analysis.TokenStream; |
| import org.apache.lucene.analysis.Tokenizer; |
| import org.apache.lucene.util.IOUtils; |
| import org.apache.lucene.util.Version; |
| |
| /** |
| * {@link Analyzer} for Russian 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> |
| * <a name="version"/> |
| * <p>You may specify the {@link Version} |
| * compatibility when creating RussianAnalyzer: |
| * <ul> |
| * <li> As of 3.1, StandardTokenizer is used, Snowball stemming is done with |
| * SnowballFilter, and Snowball stopwords are used by default. |
| * </ul> |
| */ |
| public final class RussianAnalyzer extends StopwordAnalyzerBase |
| { |
| /** |
| * List of typical Russian stopwords. (for backwards compatibility) |
| * @deprecated (3.1) Remove this for LUCENE 5.0 |
| */ |
| @Deprecated |
| private static final String[] RUSSIAN_STOP_WORDS_30 = { |
| "а", "без", "более", "бы", "был", "была", "были", "было", "быть", "в", |
| "вам", "вас", "весь", "во", "вот", "все", "всего", "всех", "вы", "где", |
| "да", "даже", "для", "до", "его", "ее", "ей", "ею", "если", "есть", |
| "еще", "же", "за", "здесь", "и", "из", "или", "им", "их", "к", "как", |
| "ко", "когда", "кто", "ли", "либо", "мне", "может", "мы", "на", "надо", |
| "наш", "не", "него", "нее", "нет", "ни", "них", "но", "ну", "о", "об", |
| "однако", "он", "она", "они", "оно", "от", "очень", "по", "под", "при", |
| "с", "со", "так", "также", "такой", "там", "те", "тем", "то", "того", |
| "тоже", "той", "только", "том", "ты", "у", "уже", "хотя", "чего", "чей", |
| "чем", "что", "чтобы", "чье", "чья", "эта", "эти", "это", "я" |
| }; |
| |
| /** File containing default Russian stopwords. */ |
| public final static String DEFAULT_STOPWORD_FILE = "russian_stop.txt"; |
| |
| private static class DefaultSetHolder { |
| /** @deprecated (3.1) remove this for Lucene 5.0 */ |
| @Deprecated |
| static final CharArraySet DEFAULT_STOP_SET_30 = CharArraySet |
| .unmodifiableSet(new CharArraySet(Version.LUCENE_CURRENT, |
| Arrays.asList(RUSSIAN_STOP_WORDS_30), false)); |
| static final CharArraySet DEFAULT_STOP_SET; |
| |
| static { |
| try { |
| DEFAULT_STOP_SET = WordlistLoader.getSnowballWordSet(IOUtils.getDecodingReader(SnowballFilter.class, |
| DEFAULT_STOPWORD_FILE, StandardCharsets.UTF_8)); |
| } 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", ex); |
| } |
| } |
| } |
| |
| private final CharArraySet stemExclusionSet; |
| |
| /** |
| * Returns an unmodifiable instance of the default stop-words set. |
| * |
| * @return an unmodifiable instance of the default stop-words set. |
| */ |
| public static CharArraySet getDefaultStopSet() { |
| return DefaultSetHolder.DEFAULT_STOP_SET; |
| } |
| |
| public RussianAnalyzer() { |
| this(DefaultSetHolder.DEFAULT_STOP_SET); |
| } |
| |
| /** |
| * @deprecated Use {@link #RussianAnalyzer()} |
| */ |
| @Deprecated |
| public RussianAnalyzer(Version matchVersion) { |
| this(matchVersion, |
| matchVersion.onOrAfter(Version.LUCENE_3_1) ? DefaultSetHolder.DEFAULT_STOP_SET |
| : DefaultSetHolder.DEFAULT_STOP_SET_30); |
| } |
| |
| /** |
| * Builds an analyzer with the given stop words |
| * |
| * @param stopwords |
| * a stopword set |
| */ |
| public RussianAnalyzer(CharArraySet stopwords) { |
| this(stopwords, CharArraySet.EMPTY_SET); |
| } |
| |
| /** |
| * @deprecated Use {@link #RussianAnalyzer(CharArraySet)} |
| */ |
| @Deprecated |
| public RussianAnalyzer(Version matchVersion, CharArraySet stopwords){ |
| this(matchVersion, stopwords, CharArraySet.EMPTY_SET); |
| } |
| |
| /** |
| * Builds an analyzer with the given stop words |
| * |
| * @param stopwords |
| * a stopword set |
| * @param stemExclusionSet a set of words not to be stemmed |
| */ |
| public RussianAnalyzer(CharArraySet stopwords, CharArraySet stemExclusionSet) { |
| super(stopwords); |
| this.stemExclusionSet = CharArraySet.unmodifiableSet(CharArraySet.copy(stemExclusionSet)); |
| } |
| |
| /** |
| * @deprecated Use {@link #RussianAnalyzer(CharArraySet)} |
| */ |
| @Deprecated |
| public RussianAnalyzer(Version matchVersion, CharArraySet stopwords, CharArraySet stemExclusionSet){ |
| super(matchVersion, stopwords); |
| this.stemExclusionSet = CharArraySet.unmodifiableSet(CharArraySet.copy(matchVersion, stemExclusionSet)); |
| } |
| |
| /** |
| * 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 StandardFilter}, {@link LowerCaseFilter}, {@link StopFilter} |
| * , {@link SetKeywordMarkerFilter} if a stem exclusion set is |
| * provided, and {@link SnowballFilter} |
| */ |
| @Override |
| protected TokenStreamComponents createComponents(String fieldName, |
| Reader reader) { |
| if (getVersion().onOrAfter(Version.LUCENE_3_1)) { |
| final Tokenizer source = new StandardTokenizer(getVersion(), reader); |
| TokenStream result = new StandardFilter(getVersion(), source); |
| result = new LowerCaseFilter(getVersion(), result); |
| result = new StopFilter(getVersion(), result, stopwords); |
| if (!stemExclusionSet.isEmpty()) result = new SetKeywordMarkerFilter( |
| result, stemExclusionSet); |
| result = new SnowballFilter(result, new org.tartarus.snowball.ext.RussianStemmer()); |
| return new TokenStreamComponents(source, result); |
| } else { |
| final Tokenizer source = new RussianLetterTokenizer(getVersion(), reader); |
| TokenStream result = new LowerCaseFilter(getVersion(), source); |
| result = new StopFilter(getVersion(), result, stopwords); |
| if (!stemExclusionSet.isEmpty()) result = new SetKeywordMarkerFilter( |
| result, stemExclusionSet); |
| result = new SnowballFilter(result, new org.tartarus.snowball.ext.RussianStemmer()); |
| return new TokenStreamComponents(source, result); |
| } |
| } |
| } |
