package org.apache.lucene.queryparser.flexible.standard.processors;
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.
*/
import java.util.List;
import org.apache.lucene.queryparser.flexible.core.QueryNodeException;
import org.apache.lucene.queryparser.flexible.core.config.QueryConfigHandler;
import org.apache.lucene.queryparser.flexible.core.nodes.FuzzyQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.QueryNode;
import org.apache.lucene.queryparser.flexible.core.processors.QueryNodeProcessorImpl;
import org.apache.lucene.queryparser.flexible.standard.config.FuzzyConfig;
import org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler.ConfigurationKeys;
import org.apache.lucene.search.FuzzyQuery;
/**
* This processor iterates the query node tree looking for every
* {@link FuzzyQueryNode}, when this kind of node is found, it checks on the
* query configuration for
* {@link ConfigurationKeys#FUZZY_CONFIG}, gets the
* fuzzy prefix length and default similarity from it and set to the fuzzy node.
* For more information about fuzzy prefix length check: {@link FuzzyQuery}. <br/>
*
* @see ConfigurationKeys#FUZZY_CONFIG
* @see FuzzyQuery
* @see FuzzyQueryNode
*/
public class FuzzyQueryNodeProcessor extends QueryNodeProcessorImpl {
@Override
protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
return node;
}
@Override
protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
if (node instanceof FuzzyQueryNode) {
FuzzyQueryNode fuzzyNode = (FuzzyQueryNode) node;
QueryConfigHandler config = getQueryConfigHandler();
FuzzyConfig fuzzyConfig = null;
if (config != null && (fuzzyConfig = config.get(ConfigurationKeys.FUZZY_CONFIG)) != null) {
fuzzyNode.setPrefixLength(fuzzyConfig.getPrefixLength());
if (fuzzyNode.getSimilarity() < 0) {
fuzzyNode.setSimilarity(fuzzyConfig.getMinSimilarity());
}
} else if (fuzzyNode.getSimilarity() < 0) {
throw new IllegalArgumentException("No FUZZY_CONFIG set in the config");
}
}
return node;
}
@Override
protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
throws QueryNodeException {
return children;
}
}