org.apache.lucene.search
Class BooleanQuery.BooleanWeight

java.lang.Object
  org.apache.lucene.search.Weight
      org.apache.lucene.search.BooleanQuery.BooleanWeight

All Implemented Interfaces:

Serializable

Enclosing class:

BooleanQuery

protected class BooleanQuery.BooleanWeight
extends Weight

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

NOTE: this API and implementation is subject to change suddenly in the next release.

See Also:

Serialized Form

Field Summary

protected Similarity	similarity The Similarity implementation.
protected ArrayList<Weight>	weights

Constructor Summary

BooleanQuery.BooleanWeight(Searcher searcher)

Method Summary

Explanation	explain(IndexReader reader, int doc) An explanation of the score computation for the named document.
Query	getQuery() The query that this concerns.
float	getValue() The weight for this query.
void	normalize(float norm) Assigns the query normalization factor to this.
Scorer	scorer(IndexReader reader, boolean scoreDocsInOrder, boolean topScorer) Returns a Scorer which scores documents in/out-of order according to scoreDocsInOrder.
boolean	scoresDocsOutOfOrder() Returns true iff this implementation scores docs only out of order.
float	sumOfSquaredWeights() The sum of squared weights of contained query clauses.

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.

weights

protected ArrayList<Weight> weights

Constructor Detail

BooleanQuery.BooleanWeight

public BooleanQuery.BooleanWeight(Searcher searcher)
                           throws IOException

Throws:

IOException

Method Detail

getQuery

public Query getQuery()

Description copied from class: Weight

The query that this concerns.

Specified by:

getQuery in class Weight

getValue

public float getValue()

Description copied from class: Weight

The weight for this query.

Specified by:

getValue in class Weight

sumOfSquaredWeights

public float sumOfSquaredWeights()
                          throws IOException

Description copied from class: Weight

The sum of squared weights of contained query clauses.

Specified by:

sumOfSquaredWeights in class Weight

Throws:

IOException

normalize

public void normalize(float norm)

Description copied from class: Weight

Assigns the query normalization factor to this.

Specified by:

normalize in class Weight

explain

public Explanation explain(IndexReader reader,
                           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:

reader - sub-reader containing the give doc

Returns:

an Explanation for the score

Throws:

IOException

scorer

public Scorer scorer(IndexReader reader,
                     boolean scoreDocsInOrder,
                     boolean topScorer)
              throws IOException

Description copied from class: Weight

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

NOTE: even if scoreDocsInOrder is false, it is recommended to check whether the returned Scorer indeed scores documents out of order (i.e., call Weight.scoresDocsOutOfOrder()), as some Scorer implementations will always return documents in-order.
NOTE: null can be returned if no documents will be scored by this query.

Specified by:

scorer in class Weight

Parameters:

reader - the IndexReader for which to return the Scorer.

scoreDocsInOrder - specifies whether in-order scoring of documents is required. Note that if set to false (i.e., out-of-order scoring is required), this method can return whatever scoring mode it supports, as every in-order scorer is also an out-of-order one. However, an out-of-order scorer may not support DocIdSetIterator.nextDoc() and/or DocIdSetIterator.advance(int), therefore it is recommended to request an in-order scorer if use of these methods is required.

topScorer - if true, Scorer.score(Collector) will be called; if false, DocIdSetIterator.nextDoc() and/or DocIdSetIterator.advance(int) will be called.

Returns:

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

Throws:

IOException

scoresDocsOutOfOrder

public boolean scoresDocsOutOfOrder()

Description copied from class: Weight

Returns true iff this implementation scores docs only out of order. This method is used in conjunction with Collector's acceptsDocsOutOfOrder and Weight.scorer(org.apache.lucene.index.IndexReader, boolean, boolean) to create a matching Scorer instance for a given Collector, or vice versa.

NOTE: the default implementation returns false, i.e. the Scorer scores documents in-order.

Overrides:

scoresDocsOutOfOrder in class Weight