Module org.apache.lucene.core

Package org.apache.lucene.search

Class SynonymQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.SynonymQuery

public final class SynonymQuery
extends Query

A query that treats multiple terms as synonyms.

For scoring purposes, this query tries to score the terms as if you had indexed them as one term: it will match any of the terms but only invoke the similarity a single time, scoring the sum of all term frequencies for the document.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SynonymQuery.Builder	A builder for SynonymQuery.
private static class	SynonymQuery.DisiWrapperFreq
private static class	SynonymQuery.FreqBoostTermScorer
private static class	SynonymQuery.SynonymScorer
(package private) class	SynonymQuery.SynonymWeight
private static class	SynonymQuery.TermAndBoost

Field Summary

Fields

Modifier and Type	Field	Description
private final String	field
private final SynonymQuery.TermAndBoost[]	terms

Constructor Summary

Constructors

Modifier	Constructor	Description
private	SynonymQuery(SynonymQuery.TermAndBoost[] terms, String field)	Creates a new SynonymQuery, matching any of the supplied terms.

Method Summary

Modifier and Type	Method	Description
Weight	createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)	Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object other)	Override and implement query instance equivalence properly in a subclass.
String	getField()	Returns the field name of this SynonymQuery
List<Term>	getTerms()	Returns the terms of this SynonymQuery
int	hashCode()	Override and implement query hash code properly in a subclass.
(package private) static ImpactsSource	mergeImpacts(ImpactsEnum[] impactsEnums, float[] boosts)	Merge impacts for multiple synonyms.
Query	rewrite(IndexSearcher indexSearcher)	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.
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

Methods inherited from class java.lang.Object

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

Field Details

terms

private final SynonymQuery.TermAndBoost[] terms

field

private final String field

Constructor Details

SynonymQuery

private SynonymQuery(SynonymQuery.TermAndBoost[] terms,
 String field)

Creates a new SynonymQuery, matching any of the supplied terms.

The terms must all have the same field.

Method Details

getTerms

public List<Term> getTerms()

Returns the terms of this SynonymQuery

getField

public String getField()

Returns the field name of this SynonymQuery

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

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)

equals

public boolean equals(Object other)

Description copied from class: Query

Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache 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 class Query

See Also:

• Query.sameClassAs(Object)
• Query.classHash()

rewrite

public Query rewrite(IndexSearcher indexSearcher)
              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.

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 class Query

Throws:

IOException

See Also:

• IndexSearcher.rewrite(Query)

visit

public void visit(QueryVisitor visitor)

Description copied from class: Query

Recurse through the query tree, visiting any child queries.

Specified by:

visit in class Query

Parameters:

visitor - a QueryVisitor to be called by each query in the tree

createWeight

public Weight createWeight(IndexSearcher searcher,
 ScoreMode scoreMode,
 float boost)
                    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

Parameters:

scoreMode - How the produced scorers will be consumed.

boost - The boost that is propagated by the parent queries.

Throws:

IOException

mergeImpacts

static ImpactsSource mergeImpacts(ImpactsEnum[] impactsEnums,
 float[] boosts)

Merge impacts for multiple synonyms.