| /* |
| * 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.classic; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| import org.apache.lucene.analysis.CharArraySet; |
| import org.apache.lucene.analysis.LowerCaseFilter; |
| import org.apache.lucene.analysis.StopFilter; |
| import org.apache.lucene.analysis.StopwordAnalyzerBase; |
| import org.apache.lucene.analysis.TokenStream; |
| import org.apache.lucene.analysis.WordlistLoader; |
| import org.apache.lucene.analysis.en.EnglishAnalyzer; |
| import org.apache.lucene.analysis.standard.StandardAnalyzer; |
| |
| /** |
| * Filters {@link ClassicTokenizer} with {@link ClassicFilter}, {@link LowerCaseFilter} and {@link |
| * StopFilter}, using a list of English stop words. |
| * |
| * <p>ClassicAnalyzer was named StandardAnalyzer in Lucene versions prior to 3.1. As of 3.1, {@link |
| * StandardAnalyzer} implements Unicode text segmentation, as specified by UAX#29. |
| * |
| * @since 3.1 |
| */ |
| public final class ClassicAnalyzer extends StopwordAnalyzerBase { |
| |
| /** Default maximum allowed token length */ |
| public static final int DEFAULT_MAX_TOKEN_LENGTH = 255; |
| |
| private int maxTokenLength = DEFAULT_MAX_TOKEN_LENGTH; |
| |
| /** |
| * An unmodifiable set containing some common English words that are usually not useful for |
| * searching. |
| */ |
| public static final CharArraySet STOP_WORDS_SET = EnglishAnalyzer.ENGLISH_STOP_WORDS_SET; |
| |
| /** |
| * Builds an analyzer with the given stop words. |
| * |
| * @param stopWords stop words |
| */ |
| public ClassicAnalyzer(CharArraySet stopWords) { |
| super(stopWords); |
| } |
| |
| /** Builds an analyzer with the default stop words ({@link #STOP_WORDS_SET}). */ |
| public ClassicAnalyzer() { |
| this(STOP_WORDS_SET); |
| } |
| |
| /** |
| * Builds an analyzer with the stop words from the given reader. |
| * |
| * @see WordlistLoader#getWordSet(Reader) |
| * @param stopwords Reader to read stop words from |
| */ |
| public ClassicAnalyzer(Reader stopwords) throws IOException { |
| this(loadStopwordSet(stopwords)); |
| } |
| |
| /** |
| * Set maximum allowed token length. If a token is seen that exceeds this length then it is |
| * discarded. This setting only takes effect the next time tokenStream or tokenStream is called. |
| */ |
| public void setMaxTokenLength(int length) { |
| maxTokenLength = length; |
| } |
| |
| /** @see #setMaxTokenLength */ |
| public int getMaxTokenLength() { |
| return maxTokenLength; |
| } |
| |
| @Override |
| protected TokenStreamComponents createComponents(final String fieldName) { |
| final ClassicTokenizer src = new ClassicTokenizer(); |
| src.setMaxTokenLength(maxTokenLength); |
| TokenStream tok = new ClassicFilter(src); |
| tok = new LowerCaseFilter(tok); |
| tok = new StopFilter(tok, stopwords); |
| return new TokenStreamComponents( |
| r -> { |
| src.setMaxTokenLength(ClassicAnalyzer.this.maxTokenLength); |
| src.setReader(r); |
| }, |
| tok); |
| } |
| |
| @Override |
| protected TokenStream normalize(String fieldName, TokenStream in) { |
| return new LowerCaseFilter(in); |
| } |
| } |