org.apache.lucene.search

Interface Weight

All Superinterfaces:
java.io.Serializable

public interface Weight
extends java.io.Serializable

Expert: Calculate query weights and build query scorers.

A Weight is constructed by a query, given a Searcher (Query.createWeight(Searcher)). The sumOfSquaredWeights() method is then called on the top-level query to compute the query normalization factor (@link Similarity#queryNorm(float)}). This factor is then passed to normalize(float). At this point the weighting is complete and a scorer may be constructed by calling scorer(IndexReader).

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)
Constructs a scorer for this.
float
sumOfSquaredWeights()
The sum of squared weights of contained query clauses.

Method Details

explain

public Explanation explain(IndexReader reader,
                           int doc)
            throws IOException
An explanation of the score computation for the named document.


getQuery

public Query getQuery()
The query that this concerns.


getValue

public float getValue()
The weight for this query.


normalize

public void normalize(float norm)
Assigns the query normalization factor to this.


scorer

public Scorer scorer(IndexReader reader)
            throws IOException
Constructs a scorer for this.


sumOfSquaredWeights

public float sumOfSquaredWeights()
            throws IOException
The sum of squared weights of contained query clauses.


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