public class AutomatonQuery extends MultiTermQuery
Query
that will match terms against a finite-state machine.
This query will match documents that contain terms accepted by a given
finite-state machine. The automaton can be constructed with the
org.apache.lucene.util.automaton
API. Alternatively, it can be
created from a regular expression with RegexpQuery
or from
the standard Lucene wildcard syntax with WildcardQuery
.
When the query is executed, it will create an equivalent DFA of the
finite-state machine, and will enumerate the term dictionary in an
intelligent way to reduce the number of comparisons. For example: the regular
expression of [dl]og?
will make approximately four comparisons:
do, dog, lo, and log.
MultiTermQuery.ConstantScoreAutoRewrite, MultiTermQuery.RewriteMethod, MultiTermQuery.TopTermsBoostOnlyBooleanQueryRewrite, MultiTermQuery.TopTermsScoringBooleanQueryRewrite
Modifier and Type | Field and Description |
---|---|
protected Automaton |
automaton
the automaton to match index terms against
|
protected CompiledAutomaton |
compiled |
protected Term |
term
term containing the field, and possibly some pattern structure
|
CONSTANT_SCORE_AUTO_REWRITE_DEFAULT, CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE, CONSTANT_SCORE_FILTER_REWRITE, field, rewriteMethod, SCORING_BOOLEAN_QUERY_REWRITE
Constructor and Description |
---|
AutomatonQuery(Term term,
Automaton automaton)
Create a new AutomatonQuery from an
Automaton . |
Modifier and Type | Method and Description |
---|---|
boolean |
equals(Object obj) |
protected TermsEnum |
getTermsEnum(Terms terms,
AttributeSource atts)
Construct the enumeration to be used, expanding the
pattern term.
|
int |
hashCode() |
String |
toString(String field)
Prints a query to a string, with
field assumed to be the
default field and omitted. |
getField, getRewriteMethod, getTermsEnum, rewrite, setRewriteMethod
clone, createWeight, extractTerms, getBoost, setBoost, toString
protected final Automaton automaton
protected final CompiledAutomaton compiled
protected final Term term
protected TermsEnum getTermsEnum(Terms terms, AttributeSource atts) throws IOException
MultiTermQuery
TermsEnum.EMPTY
if no
terms match). The TermsEnum must already be
positioned to the first matching term.
The given AttributeSource
is passed by the MultiTermQuery.RewriteMethod
to
provide attributes, the rewrite method uses to inform about e.g. maximum competitive boosts.
This is currently only used by TopTermsRewrite
getTermsEnum
in class MultiTermQuery
IOException
public int hashCode()
hashCode
in class MultiTermQuery
public boolean equals(Object obj)
equals
in class MultiTermQuery
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