org.apache.lucene.search

Class HitCollector

java.lang.Object

org.apache.lucene.search.HitCollector

Direct Known Subclasses:

TopDocCollector

public abstract class HitCollector
extends java.lang.Object

Lower-level search API.
HitCollectors are primarily meant to be used to implement queries, sorting and filtering.

See Also:

Searcher.search(Query,HitCollector)

Constructor Summary

Constructors

Constructor and Description
HitCollector()

Method Summary

Modifier and Type	Method and Description
abstract void	collect(int doc, float score) Called once for every document matching a query, with the document number and its raw score.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HitCollector

public HitCollector()

Method Detail

collect

public abstract void collect(int doc,
                             float score)

Called once for every document matching a query, with the document number and its raw score.

If, for example, an application wished to collect all of the hits for a query in a BitSet, then it might:

   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);
       }
     });
 

Note: This is called in an inner search loop. For good search performance, implementations of this method should not call Searcher.doc(int) or IndexReader.document(int) on every document number encountered. Doing so can slow searches by an order of magnitude or more.

Note: The score 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.