package org.elasticsearch.index.analysis;
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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 org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.en.EnglishPossessiveFilter;
import org.apache.lucene.analysis.tr.TurkishLowerCaseFilter;
import org.apache.lucene.analysis.core.LowerCaseFilter;
import org.apache.lucene.analysis.core.StopFilter;
import org.apache.lucene.analysis.snowball.SnowballFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;
import org.apache.lucene.analysis.standard.std40.StandardTokenizer40;
import org.apache.lucene.analysis.util.CharArraySet;
import org.apache.lucene.util.Version;
/** Filters {@link StandardTokenizer} with {@link StandardFilter}, {@link
* LowerCaseFilter}, {@link StopFilter} and {@link SnowballFilter}.
*
* Available stemmers are listed in org.tartarus.snowball.ext. The name of a
* stemmer is the part of the class name before "Stemmer", e.g., the stemmer in
* {@link org.tartarus.snowball.ext.EnglishStemmer} is named "English".
* @deprecated (3.1) Use the language-specific analyzer in modules/analysis instead.
* This analyzer WAS removed in Lucene 5.0
*/
@Deprecated
public final class SnowballAnalyzer extends Analyzer {
private String name;
private CharArraySet stopSet;
/** Builds the named analyzer with no stop words. */
public SnowballAnalyzer(String name) {
this.name = name;
}
/** Builds the named analyzer with the given stop words. */
public SnowballAnalyzer(String name, CharArraySet stopWords) {
this(name);
stopSet = CharArraySet.unmodifiableSet(CharArraySet.copy(stopWords));
}
/** Constructs a {@link StandardTokenizer} filtered by a {@link
StandardFilter}, a {@link LowerCaseFilter}, a {@link StopFilter},
and a {@link SnowballFilter} */
@Override
public TokenStreamComponents createComponents(String fieldName) {
final Tokenizer tokenizer;
if (getVersion().onOrAfter(Version.LUCENE_4_7_0)) {
tokenizer = new StandardTokenizer();
} else {
tokenizer = new StandardTokenizer40();
}
TokenStream result = tokenizer;
// remove the possessive 's for english stemmers
if (name.equals("English") || name.equals("Porter") || name.equals("Lovins"))
result = new EnglishPossessiveFilter(result);
// Use a special lowercase filter for turkish, the stemmer expects it.
if (name.equals("Turkish"))
result = new TurkishLowerCaseFilter(result);
else
result = new LowerCaseFilter(result);
if (stopSet != null)
result = new StopFilter(result, stopSet);
result = new SnowballFilter(result, name);
return new TokenStreamComponents(tokenizer, result);
}
}