org.apache.lucene.search

Class RandomApproximationQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.RandomApproximationQuery

All Implemented Interfaces:

Cloneable

public class RandomApproximationQuery
extends Query

A Query that adds random approximations to its scorers.

Constructor Summary

Constructors

Constructor and Description
RandomApproximationQuery(Query query, Random random)

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 obj)
int	hashCode()
Query	rewrite(IndexReader reader) Expert: called to re-write queries into primitive queries.
String	toString(String field) Prints a query to a string, with field assumed to be the default field and omitted.

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

clone, getBoost, setBoost, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomApproximationQuery

public RandomApproximationQuery(Query query,
                                Random random)

Method Detail

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

equals

public boolean equals(Object obj)

Overrides:

equals in class Query

hashCode

public int hashCode()

Overrides:

hashCode in class Query

toString

public String toString(String field)

Description copied from class: Query

Prints a query to a string, with field assumed to be the default field and omitted.

Specified by:

toString in class Query

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