Class FunctionScoreQuery
- java.lang.Object
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- org.apache.lucene.search.Query
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- org.apache.lucene.queries.function.FunctionScoreQuery
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public final class FunctionScoreQuery extends Query
A query that wraps another query, and uses a DoubleValuesSource to replace or modify the wrapped query's scoreIf the DoubleValuesSource doesn't return a value for a particular document, then that document will be given a score of 0.
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Nested Class Summary
Nested Classes Modifier and Type Class Description private static class
FunctionScoreQuery.FunctionScoreWeight
(package private) static class
FunctionScoreQuery.MultiplicativeBoostValuesSource
private static class
FunctionScoreQuery.QueryBoostValuesSource
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Field Summary
Fields Modifier and Type Field Description private Query
in
private DoubleValuesSource
source
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Constructor Summary
Constructors Constructor Description FunctionScoreQuery(Query in, DoubleValuesSource source)
Create a new FunctionScoreQuery
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description static FunctionScoreQuery
boostByQuery(Query in, Query boostMatch, float boostValue)
Returns a FunctionScoreQuery where the scores of a wrapped query are multiplied by a boost factor if the document being scored also matches a separate boosting query.static FunctionScoreQuery
boostByValue(Query in, DoubleValuesSource boost)
Returns a FunctionScoreQuery where the scores of a wrapped query are multiplied by the value of a DoubleValuesSource.Weight
createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)
Expert: Constructs an appropriate Weight implementation for this query.boolean
equals(java.lang.Object o)
Override and implement query instance equivalence properly in a subclass.DoubleValuesSource
getSource()
Query
getWrappedQuery()
int
hashCode()
Override and implement query hash code properly in a subclass.Query
rewrite(IndexSearcher indexSearcher)
Expert: called to re-write queries into primitive queries.java.lang.String
toString(java.lang.String field)
Prints a query to a string, withfield
assumed to be the default field and omitted.void
visit(QueryVisitor visitor)
Recurse through the query tree, visiting any child queries.-
Methods inherited from class org.apache.lucene.search.Query
classHash, rewrite, sameClassAs, toString
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Field Detail
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in
private final Query in
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source
private final DoubleValuesSource source
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Constructor Detail
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FunctionScoreQuery
public FunctionScoreQuery(Query in, DoubleValuesSource source)
Create a new FunctionScoreQuery- Parameters:
in
- the query to wrapsource
- a source of scores
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Method Detail
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getWrappedQuery
public Query getWrappedQuery()
- Returns:
- the wrapped Query
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getSource
public DoubleValuesSource getSource()
- Returns:
- the underlying value source
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boostByValue
public static FunctionScoreQuery boostByValue(Query in, DoubleValuesSource boost)
Returns a FunctionScoreQuery where the scores of a wrapped query are multiplied by the value of a DoubleValuesSource.If the source has no value for a particular document, the score for that document is preserved as-is.
- Parameters:
in
- the query to boostboost
- aDoubleValuesSource
containing the boost values
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boostByQuery
public static FunctionScoreQuery boostByQuery(Query in, Query boostMatch, float boostValue)
Returns a FunctionScoreQuery where the scores of a wrapped query are multiplied by a boost factor if the document being scored also matches a separate boosting query.Documents that do not match the boosting query have their scores preserved.
This may be used to 'demote' documents that match the boosting query, by passing in a boostValue between 0 and 1.
- Parameters:
in
- the query to boostboostMatch
- the boosting queryboostValue
- the amount to boost documents which match the boosting query
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createWeight
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws java.io.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 classQuery
scoreMode
- How the produced scorers will be consumed.boost
- The boost that is propagated by the parent queries.- Throws:
java.io.IOException
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rewrite
public Query rewrite(IndexSearcher indexSearcher) throws java.io.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.Callers are expected to call
rewrite
multiple times if necessary, until the rewritten query is the same as the original query.The rewrite process may be able to make use of IndexSearcher's executor and be executed in parallel if the executor is provided.
However, if any of the intermediary queries do not satisfy the new API, parallel rewrite is not possible for any subsequent sub-queries. To take advantage of this API, the entire query tree must override this method.
- Overrides:
rewrite
in classQuery
- Throws:
java.io.IOException
- See Also:
IndexSearcher.rewrite(Query)
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visit
public void visit(QueryVisitor visitor)
Description copied from class:Query
Recurse through the query tree, visiting any child queries.
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toString
public java.lang.String toString(java.lang.String field)
Description copied from class:Query
Prints a query to a string, withfield
assumed to be the default field and omitted.
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equals
public boolean equals(java.lang.Object o)
Description copied from class:Query
Override and implement query instance equivalence properly in a subclass. This is required so thatQueryCache
works properly.Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical to those of the other instance. Utility methods are provided for certain repetitive code.
- Specified by:
equals
in classQuery
- See Also:
Query.sameClassAs(Object)
,Query.classHash()
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hashCode
public int hashCode()
Description copied from class:Query
Override and implement query hash code properly in a subclass. This is required so thatQueryCache
works properly.- Specified by:
hashCode
in classQuery
- See Also:
Query.equals(Object)
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