/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search 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.query;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.search.Query;
import org.elasticsearch.common.collect.Lists;
import org.elasticsearch.common.collect.Sets;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.lucene.search.MoreLikeThisQuery;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.mapper.internal.AllFieldMapper;
import java.io.IOException;
import java.util.List;
import java.util.Set;
/**
* @author kimchy (shay.banon)
*/
public class MoreLikeThisQueryParser implements QueryParser {
public static final String NAME = "mlt";
@Inject public MoreLikeThisQueryParser() {
}
@Override public String[] names() {
return new String[]{NAME, "more_like_this", "moreLikeThis"};
}
@Override public Query parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
XContentParser parser = parseContext.parser();
MoreLikeThisQuery mltQuery = new MoreLikeThisQuery();
mltQuery.setMoreLikeFields(new String[]{AllFieldMapper.NAME});
mltQuery.setSimilarity(parseContext.searchSimilarity());
Analyzer analyzer = null;
XContentParser.Token token;
String currentFieldName = null;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (token.isValue()) {
if ("like_text".equals(currentFieldName) || "likeText".equals(currentFieldName)) {
mltQuery.setLikeText(parser.text());
} else if ("min_term_freq".equals(currentFieldName) || "minTermFreq".equals(currentFieldName)) {
mltQuery.setMinTermFrequency(parser.intValue());
} else if ("max_query_terms".equals(currentFieldName) || "maxQueryTerms".equals(currentFieldName)) {
mltQuery.setMaxQueryTerms(parser.intValue());
} else if ("min_doc_freq".equals(currentFieldName) || "minDocFreq".equals(currentFieldName)) {
mltQuery.setMinDocFreq(parser.intValue());
} else if ("max_doc_freq".equals(currentFieldName) || "maxDocFreq".equals(currentFieldName)) {
mltQuery.setMaxDocFreq(parser.intValue());
} else if ("min_word_len".equals(currentFieldName) || "minWordLen".equals(currentFieldName)) {
mltQuery.setMinWordLen(parser.intValue());
} else if ("max_word_len".equals(currentFieldName) || "maxWordLen".equals(currentFieldName)) {
mltQuery.setMaxWordLen(parser.intValue());
} else if ("boost_terms".equals(currentFieldName) || "boostTerms".equals(currentFieldName)) {
mltQuery.setBoostTerms(true);
mltQuery.setBoostTermsFactor(parser.floatValue());
} else if ("percent_terms_to_match".equals(currentFieldName) || "percentTermsToMatch".equals(currentFieldName)) {
mltQuery.setPercentTermsToMatch(parser.floatValue());
} else if ("analyzer".equals(currentFieldName)) {
analyzer = parseContext.analysisService().analyzer(parser.text());
}
} else if (token == XContentParser.Token.START_ARRAY) {
if ("stop_words".equals(currentFieldName) || "stopWords".equals(currentFieldName)) {
Set<String> stopWords = Sets.newHashSet();
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
stopWords.add(parser.text());
}
mltQuery.setStopWords(stopWords);
} else if ("fields".equals(currentFieldName)) {
List<String> fields = Lists.newArrayList();
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
fields.add(parseContext.indexName(parser.text()));
}
mltQuery.setMoreLikeFields(fields.toArray(new String[fields.size()]));
}
}
}
if (mltQuery.getLikeText() == null) {
throw new QueryParsingException(parseContext.index(), "more_like_this requires 'like_text' to be specified");
}
if (mltQuery.getMoreLikeFields() == null || mltQuery.getMoreLikeFields().length == 0) {
throw new QueryParsingException(parseContext.index(), "more_like_this requires 'fields' to be specified");
}
if (analyzer == null) {
analyzer = parseContext.mapperService().searchAnalyzer();
}
mltQuery.setAnalyzer(analyzer);
return mltQuery;
}
}