org.apache.lucene.search
Class BoostingQuery
java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.search.BoostingQuery
- All Implemented Interfaces:
- Serializable, Cloneable
public class BoostingQuery
- extends org.apache.lucene.search.Query
The BoostingQuery class can be used to effectively demote results that match a given query.
Unlike the "NOT" clause, this still selects documents that contain undesirable terms,
but reduces their overall score:
Query balancedQuery = new BoostingQuery(positiveQuery, negativeQuery, 0.01f);
In this scenario the positiveQuery contains the mandatory, desirable criteria which is used to
select all matching documents, and the negativeQuery contains the undesirable elements which
are simply used to lessen the scores. Documents that match the negativeQuery have their score
multiplied by the supplied "boost" parameter, so this should be less than 1 to achieve a
demoting effect
This code was originally made available here: [WWW] http://marc.theaimsgroup.com/?l=lucene-user&m=108058407130459&w=2
and is documented here: http://wiki.apache.org/lucene-java/CommunityContributions
- See Also:
- Serialized Form
Constructor Summary |
BoostingQuery(org.apache.lucene.search.Query match,
org.apache.lucene.search.Query context,
float boost)
|
Methods inherited from class org.apache.lucene.search.Query |
clone, combine, createWeight, extractTerms, getBoost, getSimilarity, mergeBooleanQueries, setBoost, toString, weight |
BoostingQuery
public BoostingQuery(org.apache.lucene.search.Query match,
org.apache.lucene.search.Query context,
float boost)
rewrite
public org.apache.lucene.search.Query rewrite(org.apache.lucene.index.IndexReader reader)
throws IOException
- Overrides:
rewrite
in class org.apache.lucene.search.Query
- Throws:
IOException
hashCode
public int hashCode()
- Overrides:
hashCode
in class org.apache.lucene.search.Query
equals
public boolean equals(Object obj)
- Overrides:
equals
in class org.apache.lucene.search.Query
toString
public String toString(String field)
- Specified by:
toString
in class org.apache.lucene.search.Query
Copyright © 2000-2011 Apache Software Foundation. All Rights Reserved.