Lucene example source code file (PayloadFunction.java)

This example Lucene source code file (PayloadFunction.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

explain, explanation, explanation, function, function, io, override, override, payload, payloadfunction, serializable, string, string, unimpl

The Lucene PayloadFunction.java source code

package org.apache.lucene.search.payloads;
/**
 * 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.io.Serializable;
import org.apache.lucene.search.Explanation;

/**
 * An abstract class that defines a way for Payload*Query instances to transform
 * the cumulative effects of payload scores for a document.
 * 
 * @see org.apache.lucene.search.payloads.PayloadTermQuery for more information
 * 
 * @lucene.experimental This class and its derivations are experimental and subject to
 *               change
 * 
 **/
public abstract class PayloadFunction implements Serializable {

  /**
   * Calculate the score up to this point for this doc and field
   * @param docId The current doc
   * @param field The field
   * @param start The start position of the matching Span
   * @param end The end position of the matching Span
   * @param numPayloadsSeen The number of payloads seen so far
   * @param currentScore The current score so far
   * @param currentPayloadScore The score for the current payload
   * @return The new current Score
   *
   * @see org.apache.lucene.search.spans.Spans
   */
  public abstract float currentScore(int docId, String field, int start, int end, int numPayloadsSeen, float currentScore, float currentPayloadScore);

  /**
   * Calculate the final score for all the payloads seen so far for this doc/field
   * @param docId The current doc
   * @param field The current field
   * @param numPayloadsSeen The total number of payloads seen on this document
   * @param payloadScore The raw score for those payloads
   * @return The final score for the payloads
   */
  public abstract float docScore(int docId, String field, int numPayloadsSeen, float payloadScore);
  
  public Explanation explain(int docId, int numPayloadsSeen, float payloadScore){
	  Explanation result = new Explanation();
	  result.setDescription("Unimpl Payload Function Explain");
	  result.setValue(1);
	  return result;
  };
  
  @Override
  public abstract int hashCode();
  
  @Override
  public abstract boolean equals(Object o);

}