Class AutomatonQuery
- All Implemented Interfaces:
Accountable
- Direct Known Subclasses:
PrefixQuery
,RegexpQuery
,TermRangeQuery
,WildcardQuery
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.
- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.search.MultiTermQuery
MultiTermQuery.RewriteMethod, MultiTermQuery.TopTermsBlendedFreqScoringRewrite, MultiTermQuery.TopTermsBoostOnlyBooleanQueryRewrite, MultiTermQuery.TopTermsScoringBooleanQueryRewrite
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Field Summary
Modifier and TypeFieldDescriptionprotected final Automaton
the automaton to match index terms againstprotected final boolean
protected final CompiledAutomaton
protected final Term
term containing the field, and possibly some pattern structureFields 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
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Constructor Summary
ConstructorDescriptionAutomatonQuery
(Term term, Automaton automaton) Create a new AutomatonQuery from anAutomaton
.AutomatonQuery
(Term term, Automaton automaton, int determinizeWorkLimit) Create a new AutomatonQuery from anAutomaton
.AutomatonQuery
(Term term, Automaton automaton, int determinizeWorkLimit, boolean isBinary) Create a new AutomatonQuery from anAutomaton
.AutomatonQuery
(Term term, Automaton automaton, int determinizeWorkLimit, boolean isBinary, MultiTermQuery.RewriteMethod rewriteMethod) Create a new AutomatonQuery from anAutomaton
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Method Summary
Modifier and TypeMethodDescriptionboolean
Override and implement query instance equivalence properly in a subclass.Returns the automaton used to create this queryprotected TermsEnum
getTermsEnum
(Terms terms, AttributeSource atts) Construct the enumeration to be used, expanding the pattern term.int
hashCode()
Override and implement query hash code properly in a subclass.boolean
Is this a binary (byte) oriented automaton.long
Return the memory usage of this object in bytes.Prints a query to a string, withfield
assumed to be the default field and omitted.void
visit
(QueryVisitor visitor) Recurse through the query tree, visiting any child queriesMethods 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
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Field Details
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automaton
the automaton to match index terms against -
compiled
-
term
term containing the field, and possibly some pattern structure -
automatonIsBinary
protected final boolean automatonIsBinary
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Constructor Details
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AutomatonQuery
Create a new AutomatonQuery from anAutomaton
.- Parameters:
term
- Term containing field and possibly some pattern structure. The term text is ignored.automaton
- Automaton to run, terms that are accepted are considered a match.
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AutomatonQuery
Create a new AutomatonQuery from anAutomaton
.- Parameters:
term
- Term containing field and possibly some pattern structure. The term text is ignored.automaton
- Automaton to run, terms that are accepted are considered a match.determinizeWorkLimit
- maximum effort to spend determinizing the automaton. If the automaton would need more than this much effort, TooComplexToDeterminizeException is thrown. Higher numbers require more space but can process more complex automata.
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AutomatonQuery
Create a new AutomatonQuery from anAutomaton
.- Parameters:
term
- Term containing field and possibly some pattern structure. The term text is ignored.automaton
- Automaton to run, terms that are accepted are considered a match.determinizeWorkLimit
- maximum effort to spend determinizing the automaton. If the automaton will need more than this much effort, TooComplexToDeterminizeException is thrown. Higher numbers require more space but can process more complex automata.isBinary
- if true, this automaton is already binary and will not go through the UTF32ToUTF8 conversion
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AutomatonQuery
public AutomatonQuery(Term term, Automaton automaton, int determinizeWorkLimit, boolean isBinary, MultiTermQuery.RewriteMethod rewriteMethod) Create a new AutomatonQuery from anAutomaton
.- Parameters:
term
- Term containing field and possibly some pattern structure. The term text is ignored.automaton
- Automaton to run, terms that are accepted are considered a match.isBinary
- if true, this automaton is already binary and will not go through the UTF32ToUTF8 conversionrewriteMethod
- the rewriteMethod to use to build the final query from the automaton
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Method Details
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getTermsEnum
Description copied from class:MultiTermQuery
Construct the enumeration to be used, expanding the pattern term. This method should only be called if the field exists (ie, implementations can assume the field does exist). This method should not return null (should instead returnTermsEnum.EMPTY
if no terms match). The TermsEnum must already be positioned to the first matching term. The givenAttributeSource
is passed by theMultiTermQuery.RewriteMethod
to share information between segments, for exampleTopTermsRewrite
uses it to share maximum competitive boosts- Specified by:
getTermsEnum
in classMultiTermQuery
- Throws:
IOException
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hashCode
public int hashCode()Description copied from class:Query
Override and implement query hash code properly in a subclass. This is required so thatQueryCache
works properly.- Overrides:
hashCode
in classMultiTermQuery
- See Also:
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equals
Description copied from class:Query
Override and implement query instance equivalence properly in a subclass. This is required so thatQueryCache
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 that other instance. Utility methods are provided for certain repetitive code.
- Overrides:
equals
in classMultiTermQuery
- See Also:
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toString
Description copied from class:Query
Prints a query to a string, withfield
assumed to be the default field and omitted. -
visit
Description copied from class:Query
Recurse through the query tree, visiting any child queries -
getAutomaton
Returns the automaton used to create this query -
isAutomatonBinary
public boolean isAutomatonBinary()Is this a binary (byte) oriented automaton. See the constructor. -
ramBytesUsed
public long ramBytesUsed()Description copied from interface:Accountable
Return the memory usage of this object in bytes. Negative values are illegal.- Specified by:
ramBytesUsed
in interfaceAccountable
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