org.apache.lucene.search

Class ScoringRewrite<Q extends Query>

java.lang.Object

org.apache.lucene.search.MultiTermQuery.RewriteMethod

org.apache.lucene.search.ScoringRewrite<Q>

public abstract class ScoringRewrite<Q extends Query>
extends MultiTermQuery.RewriteMethod

Base rewrite method that translates each term into a query, and keeps the scores as computed by the query.

Field Summary

Fields

Modifier and Type	Field and Description
static MultiTermQuery.RewriteMethod	CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE Like SCORING_BOOLEAN_QUERY_REWRITE except scores are not computed.
static ScoringRewrite<BooleanQuery>	SCORING_BOOLEAN_QUERY_REWRITE A rewrite method that first translates each term into BooleanClause.Occur.SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query.

Constructor Summary

Constructors

Constructor and Description
ScoringRewrite()

Method Summary

Modifier and Type	Method and Description
Q	rewrite(IndexReader reader, MultiTermQuery query)

Methods inherited from class java.lang.Object

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

Field Detail

SCORING_BOOLEAN_QUERY_REWRITE

public static final ScoringRewrite<BooleanQuery> SCORING_BOOLEAN_QUERY_REWRITE

A rewrite method that first translates each term into BooleanClause.Occur.SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query. Note that typically such scores are meaningless to the user, and require non-trivial CPU to compute, so it's almost always better to use MultiTermQuery.CONSTANT_SCORE_AUTO_REWRITE_DEFAULT instead.

NOTE: This rewrite method will hit BooleanQuery.TooManyClauses if the number of terms exceeds BooleanQuery.getMaxClauseCount().

See Also:

MultiTermQuery.setRewriteMethod(org.apache.lucene.search.MultiTermQuery.RewriteMethod)

CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE

public static final MultiTermQuery.RewriteMethod CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE

Like SCORING_BOOLEAN_QUERY_REWRITE except scores are not computed. Instead, each matching document receives a constant score equal to the query's boost.

NOTE: This rewrite method will hit BooleanQuery.TooManyClauses if the number of terms exceeds BooleanQuery.getMaxClauseCount().

See Also:

MultiTermQuery.setRewriteMethod(org.apache.lucene.search.MultiTermQuery.RewriteMethod)

Constructor Detail

ScoringRewrite

public ScoringRewrite()

Method Detail

rewrite

public final Q rewrite(IndexReader reader,
                       MultiTermQuery query)
                throws IOException

Specified by:

rewrite in class MultiTermQuery.RewriteMethod

Throws:

IOException