Package org.apache.lucene.queries.function

Class FunctionQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.queries.function.FunctionQuery

All Implemented Interfaces:

Cloneable

public class FunctionQuery
extends Query

Returns a score for each document based on a ValueSource, often some function of the value of a field. Note: This API is experimental and may change in non backward-compatible ways in the future

Constructor Summary

Constructors

Constructor	Description
FunctionQuery(ValueSource func)

Method Summary

Modifier and Type	Method	Description
Weight	createWeight(IndexSearcher searcher)	Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object o)	Returns true if o is equal to this.
void	extractTerms(Set<Term> terms)	Expert: adds all terms occurring in this query to the terms set.
ValueSource	getValueSource()
int	hashCode()	Returns a hash code value for this object.
Query	rewrite(IndexReader reader)	Expert: called to re-write queries into primitive queries.
String	toString(String field)	Prints a user-readable version of this query.

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

clone, getBoost, setBoost, toString

Methods inherited from class java.lang.Object

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

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

extractTerms

public void extractTerms(Set<Term> terms)

Description copied from class: Query

Expert: adds all terms occurring in this query to the terms set. Only works if this query is in its rewritten form.

Overrides:

extractTerms in class Query

createWeight

public Weight createWeight(IndexSearcher searcher)
                    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

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 o)

Returns true if o is equal to this.

Overrides:

equals in class Query

hashCode

public int hashCode()

Returns a hash code value for this object.

Overrides:

hashCode in class Query