org.apache.lucene.search

Class DisjunctionMaxQuery.DisjunctionMaxWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.DisjunctionMaxQuery.DisjunctionMaxWeight

Enclosing class:

DisjunctionMaxQuery

protected class DisjunctionMaxQuery.DisjunctionMaxWeight
extends Weight

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

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

Nested Class Summary

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

Weight.DefaultBulkScorer

Field Summary

Fields

Modifier and Type	Field and Description
protected ArrayList<Weight>	weights The Weights for our subqueries, in 1-1 correspondence with disjuncts

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

parentQuery

Constructor Summary

Constructors

Constructor and Description
DisjunctionMaxWeight(IndexSearcher searcher, boolean needsScores) Construct the Weight for this Query searched by searcher.

Method Summary

Modifier and Type	Method and Description
Explanation	explain(LeafReaderContext context, int doc) Explain the score we computed for doc
void	extractTerms(Set<Term> terms) Expert: adds all terms occurring in this query to the terms set.
float	getValueForNormalization() Compute the sub of squared weights of us applied to our subqueries.
void	normalize(float norm, float boost) Apply the computed normalization factor to our subqueries
Scorer	scorer(LeafReaderContext context) Create the scorer used to score our associated DisjunctionMaxQuery

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

bulkScorer, getQuery

Methods inherited from class java.lang.Object

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

Field Detail

weights

protected final ArrayList<Weight> weights

The Weights for our subqueries, in 1-1 correspondence with disjuncts

Constructor Detail

DisjunctionMaxWeight

public DisjunctionMaxWeight(IndexSearcher searcher,
                            boolean needsScores)
                     throws IOException

Construct the Weight for this Query searched by searcher. Recursively construct subquery weights.

Throws:

IOException

Method Detail

extractTerms

public void extractTerms(Set<Term> terms)

Description copied from class: Weight

Expert: adds all terms occurring in this query to the terms set. If the Weight was created with needsScores == true then this method will only extract terms which are used for scoring, otherwise it will extract all terms which are used for matching.

Specified by:

extractTerms in class Weight

getValueForNormalization

public float getValueForNormalization()
                               throws IOException

Compute the sub of squared weights of us applied to our subqueries. Used for normalization.

Specified by:

getValueForNormalization in class Weight

Throws:

IOException

normalize

public void normalize(float norm,
                      float boost)

Apply the computed normalization factor to our subqueries

Specified by:

normalize in class Weight

scorer

public Scorer scorer(LeafReaderContext context)
              throws IOException

Create the scorer used to score our associated DisjunctionMaxQuery

Specified by:

scorer in class Weight

Parameters:

context - the LeafReaderContext for which to return the Scorer.

Returns:

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

Throws:

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

explain

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

Explain the score we computed for doc

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