org.apache.lucene.search

Class BooleanWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.BooleanWeight

public class BooleanWeight
extends Weight

Expert: the Weight for BooleanQuery, used to normalize, score and explain these queries.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	maxCoord
protected BooleanQuery	query
protected Similarity	similarity The Similarity implementation.
protected ArrayList<Weight>	weights

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

parentQuery

Constructor Summary

Constructors

Constructor and Description
BooleanWeight(BooleanQuery query, IndexSearcher searcher, boolean needsScores, boolean disableCoord)

Method Summary

Methods

Modifier and Type	Method and Description
BulkScorer	bulkScorer(LeafReaderContext context, Bits acceptDocs) Optional method, to return a BulkScorer to score the query and send hits to a Collector.
float	coord(int overlap, int maxOverlap)
Explanation	explain(LeafReaderContext context, int doc) An explanation of the score computation for the named document.
float	getValueForNormalization() The value for normalization of contained query clauses (e.g.
void	normalize(float norm, float topLevelBoost) Assigns the query normalization factor and boost from parent queries to this.
Scorer	scorer(LeafReaderContext context, Bits acceptDocs) Returns a Scorer which scores documents in/out-of order according to scoreDocsInOrder.

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

getQuery

Methods inherited from class java.lang.Object

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

Field Detail

similarity

protected Similarity similarity

The Similarity implementation.

query

protected final BooleanQuery query

weights

protected ArrayList<Weight> weights

maxCoord

protected int maxCoord

Constructor Detail

BooleanWeight

public BooleanWeight(BooleanQuery query,
             IndexSearcher searcher,
             boolean needsScores,
             boolean disableCoord)
              throws IOException

Throws:

IOException

Method Detail

getValueForNormalization

public float getValueForNormalization()
                               throws IOException

Description copied from class: Weight

The value for normalization of contained query clauses (e.g. sum of squared weights).

Specified by:

getValueForNormalization in class Weight

Throws:

IOException

coord

public float coord(int overlap,
          int maxOverlap)

normalize

public void normalize(float norm,
             float topLevelBoost)

Description copied from class: Weight

Assigns the query normalization factor and boost from parent queries to this.

Specified by:

normalize in class Weight

explain

public Explanation explain(LeafReaderContext context,
                  int doc)
                    throws IOException

Description copied from class: Weight

An explanation of the score computation for the named document.

Specified by:

explain in class Weight

Parameters:

context - the readers context to create the Explanation for.

doc - the document's id relative to the given context's reader

Returns:

an Explanation for the score

Throws:

IOException - if an IOException occurs

bulkScorer

public BulkScorer bulkScorer(LeafReaderContext context,
                    Bits acceptDocs)
                      throws IOException

Description copied from class: Weight

Optional method, to return a BulkScorer to score the query and send hits to a Collector. Only queries that have a different top-level approach need to override this; the default implementation pulls a normal Scorer and iterates and collects the resulting hits.

Overrides:

bulkScorer in class Weight

Parameters:

context - the LeafReaderContext for which to return the Scorer.

acceptDocs - Bits that represent the allowable docs to match (typically deleted docs but possibly filtering other documents)

Returns:

a BulkScorer which scores documents and passes them to a collector.

Throws:

IOException - if there is a low-level I/O error

scorer

public Scorer scorer(LeafReaderContext context,
            Bits acceptDocs)
              throws IOException

Description copied from class: Weight

Returns a Scorer which scores documents in/out-of order according to scoreDocsInOrder.

NOTE: null can be returned if no documents will be scored by this query.

Specified by:

scorer in class Weight

Parameters:

context - the LeafReaderContext for which to return the Scorer.

acceptDocs - Bits that represent the allowable docs to match (typically deleted docs but possibly filtering other documents)

Returns:

a Scorer which scores documents in/out-of order.

Throws:

IOException - if there is a low-level I/O error