org.apache.lucene.search

Class ConstantScoreQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.ConstantScoreQuery

All Implemented Interfaces:

Cloneable

public class ConstantScoreQuery
extends Query

A query that wraps another query and simply returns a constant score equal to the query boost for every document that matches the query. It therefore simply strips of all scores and returns a constant one.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	ConstantScoreQuery.ConstantBulkScorer We return this as our BulkScorer so that if the CSQ wraps a query with its own optimized top-level scorer (e.g.

Field Summary

Fields

Modifier and Type	Field and Description
protected Query	query

Constructor Summary

Constructors

Constructor and Description
ConstantScoreQuery(Query query) Strips off scores from the passed in Query.

Method Summary

Methods

Modifier and Type	Method and Description
Weight	createWeight(IndexSearcher searcher, boolean needsScores) Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object o)
Query	getQuery() Returns the encapsulated query.
int	hashCode()
Query	rewrite(IndexReader reader) Expert: called to re-write queries into primitive queries.
String	toString(String field) Prints a query to a string, with field assumed to be the default field and omitted.

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

clone, getBoost, setBoost, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

query

protected final Query query

Constructor Detail

ConstantScoreQuery

public ConstantScoreQuery(Query query)

Strips off scores from the passed in Query. The hits will get a constant score dependent on the boost factor of this query.

Method Detail

getQuery

public Query getQuery()

Returns the encapsulated query.

rewrite

public Query rewrite(IndexReader reader)
              throws IOException

Description copied from class: Query

Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.

Overrides:

rewrite in class Query

Throws:

IOException

createWeight

public Weight createWeight(IndexSearcher searcher,
                  boolean needsScores)
                    throws IOException

Description copied from class: Query

Expert: Constructs an appropriate Weight implementation for this query.

Only implemented by primitive queries, which re-write to themselves.

Overrides:

createWeight in class Query

needsScores - True if document scores (Scorer.score()) or match frequencies (Scorer.freq()) are needed.

Throws:

IOException

toString

public String toString(String field)

Description copied from class: Query

Prints a query to a string, with field assumed to be the default field and omitted.

Specified by:

toString in class Query

equals

public boolean equals(Object o)

Overrides:

equals in class Query

hashCode

public int hashCode()

Overrides:

hashCode in class Query