package org.apache.lucene.search;
/**
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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.
*/
/** Lower-level search API.
* <br>HitCollectors are primarily meant to be used to implement queries,
* sorting and filtering.
* @see Searcher#search(Query,HitCollector)
* @version $Id: HitCollector.java 155607 2005-02-27 01:29:53Z otis $
*/
public abstract class HitCollector {
/** Called once for every non-zero scoring document, with the document number
* and its score.
*
* <P>If, for example, an application wished to collect all of the hits for a
* query in a BitSet, then it might:<pre>
* Searcher searcher = new IndexSearcher(indexReader);
* final BitSet bits = new BitSet(indexReader.maxDoc());
* searcher.search(query, new HitCollector() {
* public void collect(int doc, float score) {
* bits.set(doc);
* }
* });
* </pre>
*
* <p>Note: This is called in an inner search loop. For good search
* performance, implementations of this method should not call
* {@link Searcher#doc(int)} or
* {@link org.apache.lucene.index.IndexReader#document(int)} on every
* document number encountered. Doing so can slow searches by an order
* of magnitude or more.
* <p>Note: The <code>score</code> passed to this method is a raw score.
* In other words, the score will not necessarily be a float whose value is
* between 0 and 1.
*/
public abstract void collect(int doc, float score);
}
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