/*
 * 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.
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package org.apache.lucene.queryparser.xml.builders;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.queryparser.xml.DOMUtils;
import org.apache.lucene.queryparser.xml.ParserException;
import org.apache.lucene.queryparser.xml.QueryBuilder;
import org.apache.lucene.search.BoostQuery;
import org.apache.lucene.search.DisjunctionMaxQuery;
import org.apache.lucene.search.Query;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

Builder for DisjunctionMaxQuery
/** * Builder for {@link DisjunctionMaxQuery} */
public class DisjunctionMaxQueryBuilder implements QueryBuilder { private final QueryBuilder factory; public DisjunctionMaxQueryBuilder(QueryBuilder factory) { this.factory = factory; } /* (non-Javadoc) * @see org.apache.lucene.xmlparser.QueryObjectBuilder#process(org.w3c.dom.Element) */ @Override public Query getQuery(Element e) throws ParserException { float tieBreaker = DOMUtils.getAttribute(e, "tieBreaker", 0.0f); List<Query> disjuncts = new ArrayList<>(); NodeList nl = e.getChildNodes(); final int nlLen = nl.getLength(); for (int i = 0; i < nlLen; i++) { Node node = nl.item(i); if (node instanceof Element) { // all elements are disjuncts. Element queryElem = (Element) node; Query q = factory.getQuery(queryElem); disjuncts.add(q); } } Query q = new DisjunctionMaxQuery(disjuncts, tieBreaker); float boost = DOMUtils.getAttribute(e, "boost", 1.0f); if (boost != 1f) { q = new BoostQuery(q, boost); } return q; } }