lucene/queryparser/src/java/org/apache/lucene/queryparser/xml/builders/BoostingTermBuilder.java

/*
 * 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.
 */
package org.apache.lucene.queryparser.xml.builders;

import org.apache.lucene.index.Term;
import org.apache.lucene.queries.payloads.AveragePayloadFunction;
import org.apache.lucene.queries.payloads.PayloadDecoder;
import org.apache.lucene.queries.payloads.PayloadScoreQuery;
import org.apache.lucene.queryparser.xml.DOMUtils;
import org.apache.lucene.queryparser.xml.ParserException;
import org.apache.lucene.search.spans.SpanBoostQuery;
import org.apache.lucene.search.spans.SpanQuery;
import org.apache.lucene.search.spans.SpanTermQuery;
import org.w3c.dom.Element;

/**
 * Builder for {@link PayloadScoreQuery}
 */
public class BoostingTermBuilder extends SpanBuilderBase {

  @Override
  public SpanQuery getSpanQuery(Element e) throws ParserException {
    String fieldName = DOMUtils.getAttributeWithInheritanceOrFail(e, "fieldName");
    String value = DOMUtils.getNonBlankTextOrFail(e);

    // TODO make function and decoder pluggable somehow?
    SpanQuery btq = new PayloadScoreQuery(new SpanTermQuery(new Term(fieldName, value)),
        new AveragePayloadFunction(), PayloadDecoder.FLOAT_DECODER);
    btq = new SpanBoostQuery(btq, DOMUtils.getAttribute(e, "boost", 1.0f));
    return btq;
  }

}