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 Detail

getQuery

public Query getQuery()
The query that this concerns.


getValue

public float getValue()
The weight for this query.


sumOfSquaredWeights

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

Throws:
java.io.IOException

normalize

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


scorer

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

Throws:
java.io.IOException

explain

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

Throws:
java.io.IOException


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