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* Licensed to Elasticsearch under one or more contributor
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* 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
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package org.elasticsearch.index.analysis;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.core.Lucene43StopFilter;
import org.apache.lucene.analysis.core.StopAnalyzer;
import org.apache.lucene.analysis.core.StopFilter;
import org.apache.lucene.analysis.util.CharArraySet;
import org.apache.lucene.search.suggest.analyzing.SuggestStopFilter;
import org.apache.lucene.util.Version;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.inject.assistedinject.Assisted;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.env.Environment;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.settings.IndexSettingsService;
import java.util.Set;
@SuppressWarnings("deprecation")
public class StopTokenFilterFactory extends AbstractTokenFilterFactory {
private final CharArraySet stopWords;
private final boolean ignoreCase;
private final boolean enablePositionIncrements;
private final boolean removeTrailing;
@Inject
public StopTokenFilterFactory(Index index, IndexSettingsService indexSettingsService, Environment env, @Assisted String name, @Assisted Settings settings) {
super(index, indexSettingsService.getSettings(), name, settings);
this.ignoreCase = settings.getAsBoolean("ignore_case", false);
this.removeTrailing = settings.getAsBoolean("remove_trailing", true);
this.stopWords = Analysis.parseStopWords(env, settings, StopAnalyzer.ENGLISH_STOP_WORDS_SET, ignoreCase);
if (version.onOrAfter(Version.LUCENE_4_4) && settings.get("enable_position_increments") != null) {
throw new IllegalArgumentException("enable_position_increments is not supported anymore as of Lucene 4.4 as it can create broken token streams."
+ " Please fix your analysis chain or use an older compatibility version (<= 4.3).");
}
this.enablePositionIncrements = settings.getAsBoolean("enable_position_increments", true);
}
@Override
public TokenStream create(TokenStream tokenStream) {
if (removeTrailing) {
if (version.onOrAfter(Version.LUCENE_4_4)) {
return new StopFilter(tokenStream, stopWords);
} else {
return new Lucene43StopFilter(enablePositionIncrements, tokenStream, stopWords);
}
} else {
return new SuggestStopFilter(tokenStream, stopWords);
}
}
public Set<?> stopWords() {
return stopWords;
}
public boolean ignoreCase() {
return ignoreCase;
}
}