org.apache.lucene.search

Class BoostQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.BoostQuery

All Implemented Interfaces:

Cloneable

public final class BoostQuery
extends Query

A Query wrapper that allows to give a boost to the wrapped query. Boost values that are less than one will give less importance to this query compared to other ones while values that are greater than one will give more importance to the scores returned by this query.

Constructor Summary

Constructors

Constructor and Description
BoostQuery(Query query, float boost) Sole constructor: wrap query in such a way that the produced scores will be boosted by boost.

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 obj)
float	getBoost() Gets the boost for this clause.
Query	getQuery() Return the wrapped 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, setBoost, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

BoostQuery

public BoostQuery(Query query,
          float boost)

Sole constructor: wrap query in such a way that the produced scores will be boosted by boost.

Method Detail

getQuery

public Query getQuery()

Return the wrapped Query.

getBoost

public float getBoost()

Description copied from class: Query

Gets the boost for this clause.

Overrides:

getBoost in class Query

equals

public boolean equals(Object obj)

Overrides:

equals in class Query

hashCode

public int hashCode()

Overrides:

hashCode in class 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

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

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