org.apache.lucene.search

Class FilterScorer

java.lang.Object

org.apache.lucene.search.Scorer

org.apache.lucene.search.FilterScorer

Direct Known Subclasses:

ScoreCachingWrappingScorer

public abstract class FilterScorer
extends Scorer

A FilterScorer contains another Scorer, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality. The class FilterScorer itself simply implements all abstract methods of Scorer with versions that pass all requests to the contained scorer. Subclasses of FilterScorer may further override some of these methods and may also provide additional methods and fields.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.Scorer

Scorer.ChildScorer

Field Summary

Fields

Modifier and Type	Field and Description
protected Scorer	in

Fields inherited from class org.apache.lucene.search.Scorer

weight

Constructor Summary

Constructors

Constructor and Description
FilterScorer(Scorer in) Create a new FilterScorer
FilterScorer(Scorer in, Weight weight) Create a new FilterScorer with a specific weight

Method Summary

Modifier and Type	Method and Description
int	docID() Returns the doc ID that is currently being scored.
int	freq() Returns the freq of this Scorer on the current document
DocIdSetIterator	iterator() Return a DocIdSetIterator over matching documents.
float	score() Returns the score of the current document matching the query.
TwoPhaseIterator	twoPhaseIterator() Optional method: Return a TwoPhaseIterator view of this Scorer.

Methods inherited from class org.apache.lucene.search.Scorer

getChildren, getWeight

Methods inherited from class java.lang.Object

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

Field Detail

in

protected final Scorer in

Constructor Detail

FilterScorer

public FilterScorer(Scorer in)

Create a new FilterScorer

Parameters:

in - the Scorer to wrap

FilterScorer

public FilterScorer(Scorer in,
                    Weight weight)

Create a new FilterScorer with a specific weight

Parameters:

in - the Scorer to wrap

weight - a Weight

Method Detail

score

public float score()
            throws IOException

Description copied from class: Scorer

Returns the score of the current document matching the query. Initially invalid, until DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) is called on the Scorer.iterator() the first time, or when called from within LeafCollector.collect(int).

Specified by:

score in class Scorer

Throws:

IOException

freq

public int freq()
         throws IOException

Description copied from class: Scorer

Returns the freq of this Scorer on the current document

Specified by:

freq in class Scorer

Throws:

IOException

docID

public final int docID()

Description copied from class: Scorer

Returns the doc ID that is currently being scored. This will return -1 if the Scorer.iterator() is not positioned or DocIdSetIterator.NO_MORE_DOCS if it has been entirely consumed.

Specified by:

docID in class Scorer

See Also:

DocIdSetIterator.docID()

iterator

public final DocIdSetIterator iterator()

Description copied from class: Scorer

Return a DocIdSetIterator over matching documents. The returned iterator will either be positioned on -1 if no documents have been scored yet, DocIdSetIterator.NO_MORE_DOCS if all documents have been scored already, or the last document id that has been scored otherwise. The returned iterator is a view: calling this method several times will return iterators that have the same state.

Specified by:

iterator in class Scorer

twoPhaseIterator

public final TwoPhaseIterator twoPhaseIterator()

Description copied from class: Scorer

Optional method: Return a TwoPhaseIterator view of this Scorer. A return value of null indicates that two-phase iteration is not supported. Note that the returned TwoPhaseIterator's approximation must advance synchronously with the Scorer.iterator(): advancing the approximation must advance the iterator and vice-versa. Implementing this method is typically useful on Scorers that have a high per-document overhead in order to confirm matches. The default implementation returns null.

Overrides:

twoPhaseIterator in class Scorer