org.apache.lucene.search

Class Query

java.lang.Object

org.apache.lucene.search.Query

All Implemented Interfaces:

Cloneable

Direct Known Subclasses:

BooleanQuery, ConstantScoreQuery, DisjunctionMaxQuery, FilteredQuery, MatchAllDocsQuery, MultiPhraseQuery, MultiTermQuery, PhraseQuery, SpanQuery, TermQuery

public abstract class Query
extends Object
implements Cloneable

The abstract base class for queries.

Instantiable subclasses are:

• TermQuery
• BooleanQuery
• WildcardQuery
• PhraseQuery
• PrefixQuery
• MultiPhraseQuery
• FuzzyQuery
• RegexpQuery
• TermRangeQuery
• NumericRangeQuery
• ConstantScoreQuery
• DisjunctionMaxQuery
• MatchAllDocsQuery

See also the family of Span Queries and additional queries available in the Queries module

Constructor Summary

Constructors

Constructor and Description
Query()

Method Summary

Methods

Modifier and Type	Method and Description
Query	clone() Returns a clone of this query.
Weight	createWeight(IndexSearcher searcher) Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object obj)
void	extractTerms(Set<Term> terms) Expert: adds all terms occurring in this query to the terms set.
float	getBoost() Gets the boost for this clause.
int	hashCode()
Query	rewrite(IndexReader reader) Expert: called to re-write queries into primitive queries.
void	setBoost(float b) Sets the boost for this query clause to b.
String	toString() Prints a query to a string.
abstract String	toString(String field) Prints a query to a string, with field assumed to be the default field and omitted.

Methods inherited from class java.lang.Object

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

Constructor Detail

Query

public Query()

Method Detail

setBoost

public void setBoost(float b)

Sets the boost for this query clause to b. Documents matching this clause will (in addition to the normal weightings) have their score multiplied by b.

getBoost

public float getBoost()

Gets the boost for this clause. Documents matching this clause will (in addition to the normal weightings) have their score multiplied by b. The boost is 1.0 by default.

toString

public abstract String toString(String field)

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

toString

public String toString()

Prints a query to a string.

Overrides:

toString in class Object

createWeight

public Weight createWeight(IndexSearcher searcher)
                    throws IOException

Expert: Constructs an appropriate Weight implementation for this query.

Only implemented by primitive queries, which re-write to themselves.

Throws:

IOException

rewrite

public Query rewrite(IndexReader reader)
              throws IOException

Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.

Throws:

IOException

extractTerms

public void extractTerms(Set<Term> terms)

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

Throws:

UnsupportedOperationException - if this query is not yet rewritten

clone

public Query clone()

Returns a clone of this query.

Overrides:

clone in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object