Package org.apache.lucene.search
Class BoostingQuery
- java.lang.Object
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- org.apache.lucene.search.Query
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- org.apache.lucene.search.BoostingQuery
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- 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multiplied by the supplied "boost" parameter, so this should be less than 1 to achieve a demoting effect This code was originally made available here: [WWW] http://marc.theaimsgroup.com/?l=lucene-user&m=108058407130459&w=2 and is documented here: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
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Constructor Summary
Constructors Constructor Description BoostingQuery(org.apache.lucene.search.Query match, org.apache.lucene.search.Query context, float boost)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
equals(Object obj)
int
hashCode()
org.apache.lucene.search.Query
rewrite(org.apache.lucene.index.IndexReader reader)
String
toString(String field)
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Method Detail
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rewrite
public org.apache.lucene.search.Query rewrite(org.apache.lucene.index.IndexReader reader) throws IOException
- Overrides:
rewrite
in classorg.apache.lucene.search.Query
- Throws:
IOException
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hashCode
public int hashCode()
- Overrides:
hashCode
in classorg.apache.lucene.search.Query
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equals
public boolean equals(Object obj)
- Overrides:
equals
in classorg.apache.lucene.search.Query
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