Package org.apache.lucene.search

Class FieldExistsQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.FieldExistsQuery

Direct Known Subclasses:

DocValuesFieldExistsQuery, KnnVectorFieldExistsQuery, NormsFieldExistsQuery

public class FieldExistsQuery
extends Query

A Query that matches documents that contain either a KnnFloatVectorField, KnnByteVectorField or a field that indexes norms or doc values.

Constructor Summary

Constructors

Constructor	Description
FieldExistsQuery(String field)	Create a query that will match that have a value for the given field.

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.
static DocIdSetIterator	getDocValuesDocIdSetIterator(String field, LeafReader reader)	Returns a DocIdSetIterator from the given field or null if the field doesn't exist in the reader or if the reader has no doc values for the field.
String	getField()
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.
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

Constructor Details

FieldExistsQuery

public FieldExistsQuery(String field)

Create a query that will match that have a value for the given field.

Method Details

getDocValuesDocIdSetIterator

public static DocIdSetIterator getDocValuesDocIdSetIterator(String field,
 LeafReader reader)
                                                     throws IOException

Returns a DocIdSetIterator from the given field or null if the field doesn't exist in the reader or if the reader has no doc values for the field.

Throws:

IOException

getField

public String getField()

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

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

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()

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)

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)

createWeight

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

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.