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* 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.
*/
package org.elasticsearch.index.analysis;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.miscellaneous.StemmerOverrideFilter;
import org.apache.lucene.analysis.miscellaneous.StemmerOverrideFilter.StemmerOverrideMap;
import org.elasticsearch.ElasticsearchIllegalArgumentException;
import org.elasticsearch.common.Strings;
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.IndexSettings;
import java.io.IOException;
import java.util.List;
@AnalysisSettingsRequired
public class StemmerOverrideTokenFilterFactory extends AbstractTokenFilterFactory {
private final StemmerOverrideMap overrideMap;
@Inject
public StemmerOverrideTokenFilterFactory(Index index, @IndexSettings Settings indexSettings, Environment env, @Assisted String name, @Assisted Settings settings) throws IOException {
super(index, indexSettings, name, settings);
List<String> rules = Analysis.getWordList(env, settings, "rules");
if (rules == null) {
throw new ElasticsearchIllegalArgumentException("stemmer override filter requires either `rules` or `rules_path` to be configured");
}
StemmerOverrideFilter.Builder builder = new StemmerOverrideFilter.Builder(false);
parseRules(rules, builder, "=>");
overrideMap = builder.build();
}
@Override
public TokenStream create(TokenStream tokenStream) {
return new StemmerOverrideFilter(tokenStream, overrideMap);
}
static void parseRules(List<String> rules, StemmerOverrideFilter.Builder builder, String mappingSep) {
for (String rule : rules) {
String key, override;
List<String> mapping = Strings.splitSmart(rule, mappingSep, false);
if (mapping.size() == 2) {
key = mapping.get(0).trim();
override = mapping.get(1).trim();
} else {
throw new RuntimeException("Invalid Keyword override Rule:" + rule);
}
if (key.isEmpty() || override.isEmpty()) {
throw new RuntimeException("Invalid Keyword override Rule:" + rule);
} else {
builder.add(key, override);
}
}
}
}