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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.query;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.FuzzyQuery;
import org.apache.lucene.search.MultiTermQuery;
import org.apache.lucene.search.Query;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.unit.Fuzziness;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.mapper.MapperService;
import org.elasticsearch.index.query.support.QueryParsers;
import java.io.IOException;
import static org.elasticsearch.index.query.support.QueryParsers.wrapSmartNameQuery;
/**
*
*/
public class FuzzyQueryParser implements QueryParser {
public static final String NAME = "fuzzy";
private static final Fuzziness DEFAULT_FUZZINESS = Fuzziness.AUTO;
private static final ParseField FUZZINESS = Fuzziness.FIELD.withDeprecation("min_similarity");
@Inject
public FuzzyQueryParser() {
}
@Override
public String[] names() {
return new String[]{NAME};
}
@Override
public Query parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
XContentParser parser = parseContext.parser();
XContentParser.Token token = parser.nextToken();
if (token != XContentParser.Token.FIELD_NAME) {
throw new QueryParsingException(parseContext.index(), "[fuzzy] query malformed, no field");
}
String fieldName = parser.currentName();
String value = null;
float boost = 1.0f;
Fuzziness fuzziness = DEFAULT_FUZZINESS;
int prefixLength = FuzzyQuery.defaultPrefixLength;
int maxExpansions = FuzzyQuery.defaultMaxExpansions;
boolean transpositions = false;
String queryName = null;
MultiTermQuery.RewriteMethod rewriteMethod = null;
token = parser.nextToken();
if (token == XContentParser.Token.START_OBJECT) {
String currentFieldName = null;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else {
if ("term".equals(currentFieldName)) {
value = parser.text();
} else if ("value".equals(currentFieldName)) {
value = parser.text();
} else if ("boost".equals(currentFieldName)) {
boost = parser.floatValue();
} else if (FUZZINESS.match(currentFieldName, parseContext.parseFlags())) {
fuzziness = Fuzziness.parse(parser);
} else if ("prefix_length".equals(currentFieldName) || "prefixLength".equals(currentFieldName)) {
prefixLength = parser.intValue();
} else if ("max_expansions".equals(currentFieldName) || "maxExpansions".equals(currentFieldName)) {
maxExpansions = parser.intValue();
} else if ("transpositions".equals(currentFieldName)) {
transpositions = parser.booleanValue();
} else if ("rewrite".equals(currentFieldName)) {
rewriteMethod = QueryParsers.parseRewriteMethod(parser.textOrNull(), null);
} else if ("_name".equals(currentFieldName)) {
queryName = parser.text();
} else {
throw new QueryParsingException(parseContext.index(), "[fuzzy] query does not support [" + currentFieldName + "]");
}
}
}
parser.nextToken();
} else {
value = parser.text();
// move to the next token
parser.nextToken();
}
if (value == null) {
throw new QueryParsingException(parseContext.index(), "No value specified for fuzzy query");
}
Query query = null;
MapperService.SmartNameFieldMappers smartNameFieldMappers = parseContext.smartFieldMappers(fieldName);
if (smartNameFieldMappers != null) {
if (smartNameFieldMappers.hasMapper()) {
query = smartNameFieldMappers.mapper().fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions);
}
}
if (query == null) {
query = new FuzzyQuery(new Term(fieldName, value), fuzziness.asDistance(value), prefixLength, maxExpansions, transpositions);
}
if (query instanceof MultiTermQuery) {
QueryParsers.setRewriteMethod((MultiTermQuery) query, rewriteMethod);
}
query.setBoost(boost);
query = wrapSmartNameQuery(query, smartNameFieldMappers, parseContext);
if (queryName != null) {
parseContext.addNamedQuery(queryName, query);
}
return query;
}
}