/*
* 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.FuzzyLikeThisQuery;
import org.apache.lucene.search.Query;
import org.elasticsearch.common.collect.Lists;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.mapper.internal.AllFieldMapper;
import java.io.IOException;
import java.util.List;
/**
* <pre>
* {
* fuzzy_like_this : {
* maxNumTerms : 12,
* boost : 1.1,
* fields : ["field1", "field2"]
* likeText : "..."
* }
* }
* </pre>
*
* @author kimchy (shay.banon)
*/
public class FuzzyLikeThisQueryParser implements QueryParser {
public static final String NAME = "flt";
@Inject public FuzzyLikeThisQueryParser() {
}
@Override public String[] names() {
return new String[]{NAME, "fuzzy_like_this", "fuzzyLikeThis"};
}
@Override public Query parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
XContentParser parser = parseContext.parser();
int maxNumTerms = 25;
float boost = 1.0f;
List<String> fields = null;
String likeText = null;
float minSimilarity = 0.5f;
int prefixLength = 0;
boolean ignoreTF = false;
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)) {
likeText = parser.text();
} else if ("max_query_terms".equals(currentFieldName) || "maxQueryTerms".equals(currentFieldName)) {
maxNumTerms = parser.intValue();
} else if ("boost".equals(currentFieldName)) {
boost = parser.floatValue();
} else if ("ignore_tf".equals(currentFieldName) || "ignoreTF".equals(currentFieldName)) {
ignoreTF = parser.booleanValue();
} else if ("min_similarity".equals(currentFieldName) || "minSimilarity".equals(currentFieldName)) {
minSimilarity = parser.floatValue();
} else if ("prefix_length".equals(currentFieldName) || "prefixLength".equals(currentFieldName)) {
prefixLength = parser.intValue();
} else if ("analyzer".equals(currentFieldName)) {
analyzer = parseContext.analysisService().analyzer(parser.text());
}
} else if (token == XContentParser.Token.START_ARRAY) {
if ("fields".equals(currentFieldName)) {
fields = Lists.newArrayList();
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
fields.add(parseContext.indexName(parser.text()));
}
}
}
}
if (likeText == null) {
throw new QueryParsingException(parseContext.index(), "fuzzy_like_this requires 'like_text' to be specified");
}
if (analyzer == null) {
analyzer = parseContext.mapperService().searchAnalyzer();
}
FuzzyLikeThisQuery query = new FuzzyLikeThisQuery(maxNumTerms, analyzer);
if (fields == null) {
// add the default _all field
query.addTerms(likeText, AllFieldMapper.NAME, minSimilarity, prefixLength);
} else {
for (String field : fields) {
query.addTerms(likeText, field, minSimilarity, prefixLength);
}
}
query.setBoost(boost);
query.setIgnoreTF(ignoreTF);
return query;
}
}