Package org.apache.lucene.search

Class WildcardQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.MultiTermQuery

org.apache.lucene.search.AutomatonQuery

org.apache.lucene.search.WildcardQuery

All Implemented Interfaces:

Accountable

public class WildcardQuery
extends AutomatonQuery

Implements the wildcard search query. Supported wildcards are *, which matches any character sequence (including the empty one), and ?, which matches any single character. '\' is the escape character.

Note this query can be slow, as it needs to iterate over many terms. In order to prevent extremely slow WildcardQueries, a Wildcard term should not start with the wildcard *

This query uses the MultiTermQuery.CONSTANT_SCORE_REWRITE rewrite method.

See Also:

• AutomatonQuery

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.MultiTermQuery

MultiTermQuery.RewriteMethod, MultiTermQuery.TopTermsBlendedFreqScoringRewrite, MultiTermQuery.TopTermsBoostOnlyBooleanQueryRewrite, MultiTermQuery.TopTermsScoringBooleanQueryRewrite

Field Summary

Fields

Modifier and Type	Field	Description
static final char	WILDCARD_CHAR	Char equality with support for wildcards
static final char	WILDCARD_ESCAPE	Escape character
static final char	WILDCARD_STRING	String equality with support for wildcards

Fields inherited from class org.apache.lucene.search.AutomatonQuery

automaton, automatonIsBinary, compiled, term

Fields inherited from class org.apache.lucene.search.MultiTermQuery

CONSTANT_SCORE_BOOLEAN_REWRITE, CONSTANT_SCORE_REWRITE, field, rewriteMethod, SCORING_BOOLEAN_REWRITE

Fields inherited from interface org.apache.lucene.util.Accountable

NULL_ACCOUNTABLE

Constructor Summary

Constructors

Constructor	Description
WildcardQuery(Term term)	Constructs a query for terms matching term.
WildcardQuery(Term term, int determinizeWorkLimit)	Constructs a query for terms matching term.
WildcardQuery(Term term, int determinizeWorkLimit, MultiTermQuery.RewriteMethod rewriteMethod)	Constructs a query for terms matching term.

Method Summary

Modifier and Type	Method	Description
Term	getTerm()	Returns the pattern term.
static Automaton	toAutomaton(Term wildcardquery)	Convert Lucene wildcard syntax into an automaton.
String	toString(String field)	Prints a user-readable version of this query.

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

equals, getAutomaton, getTermsEnum, hashCode, isAutomatonBinary, ramBytesUsed, visit

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

getField, getRewriteMethod, getTermsEnum, rewrite, setRewriteMethod

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

classHash, createWeight, sameClassAs, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.util.Accountable

getChildResources

Field Details

WILDCARD_STRING

public static final char WILDCARD_STRING

String equality with support for wildcards

See Also:

• Constant Field Values

WILDCARD_CHAR

public static final char WILDCARD_CHAR

Char equality with support for wildcards

See Also:

• Constant Field Values

WILDCARD_ESCAPE

public static final char WILDCARD_ESCAPE

Escape character

See Also:

• Constant Field Values

Constructor Details

WildcardQuery

public WildcardQuery(Term term)

Constructs a query for terms matching term.

WildcardQuery

public WildcardQuery(Term term,
 int determinizeWorkLimit)

Constructs a query for terms matching term.

Parameters:

determinizeWorkLimit - maximum effort to spend while compiling the automaton from this wildcard. Set higher to allow more complex queries and lower to prevent memory exhaustion. Use Operations.DEFAULT_DETERMINIZE_WORK_LIMIT as a decent default if you don't otherwise know what to specify.

WildcardQuery

public WildcardQuery(Term term,
 int determinizeWorkLimit,
 MultiTermQuery.RewriteMethod rewriteMethod)

Constructs a query for terms matching term.

Parameters:

determinizeWorkLimit - maximum effort to spend while compiling the automaton from this wildcard. Set higher to allow more complex queries and lower to prevent memory exhaustion. Use Operations.DEFAULT_DETERMINIZE_WORK_LIMIT as a decent default if you don't otherwise know what to specify.

rewriteMethod - the rewrite method to use when building the final query

Method Details

toAutomaton

public static Automaton toAutomaton(Term wildcardquery)

Convert Lucene wildcard syntax into an automaton.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

getTerm

public Term getTerm()

Returns the pattern term.

toString

public String toString(String field)

Prints a user-readable version of this query.

Overrides:

toString in class AutomatonQuery