org.apache.lucene.queries.function

Class FunctionQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.queries.function.FunctionQuery

public class FunctionQuery
extends Query

Returns a score for each document based on a ValueSource, often some function of the value of a field.

See Also:

ValueSourceScorer

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	FunctionQuery.AllScorer
protected class	FunctionQuery.FunctionWeight

Constructor Summary

Constructors

Constructor and Description
FunctionQuery(ValueSource func)

Method Summary

Modifier and Type	Method and Description
Weight	createWeight(IndexSearcher searcher, boolean needsScores) Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object other) Returns true if o is equal to this.
ValueSource	getValueSource()
int	hashCode() Override and implement query hash code properly in a subclass.
String	toString(String field) Prints a user-readable version of this query.

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

classHash, rewrite, sameClassAs, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionQuery

public FunctionQuery(ValueSource func)

Parameters:

func - defines the function to be used for scoring

Method Detail

getValueSource

public ValueSource getValueSource()

Returns:

The associated ValueSource

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)

Prints a user-readable version of this query.

Specified by:

toString in class Query

equals

public boolean equals(Object other)

Returns true if o is equal to this.

Specified by:

equals in class Query

See Also:

Query.sameClassAs(Object), Query.classHash()

hashCode

public int hashCode()

Description copied from class: Query

Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.

Specified by:

hashCode in class Query

See Also:

Query.equals(Object)