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 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 -
Field Summary
FieldsModifier and TypeFieldDescriptionprotected final Automatonthe automaton to match index terms againstprotected final booleanprotected final CompiledAutomatonprotected final Termterm containing the field, and possibly some pattern structureFields inherited from class org.apache.lucene.search.MultiTermQuery
CONSTANT_SCORE_BLENDED_REWRITE, CONSTANT_SCORE_BOOLEAN_REWRITE, CONSTANT_SCORE_REWRITE, DOC_VALUES_REWRITE, field, rewriteMethod, SCORING_BOOLEAN_REWRITEFields inherited from interface org.apache.lucene.util.Accountable
NULL_ACCOUNTABLE -
Constructor Summary
ConstructorsConstructorDescriptionAutomatonQuery(Term term, Automaton automaton) Create a new AutomatonQuery from anAutomaton.AutomatonQuery(Term term, Automaton automaton, boolean isBinary) Create a new AutomatonQuery from anAutomaton.AutomatonQuery(Term term, Automaton automaton, boolean isBinary, MultiTermQuery.RewriteMethod rewriteMethod) Create a new AutomatonQuery from anAutomaton. -
Method Summary
Modifier and TypeMethodDescriptionbooleanOverride and implement query instance equivalence properly in a subclass.Returns the automaton used to create this queryprotected TermsEnumgetTermsEnum(Terms terms, AttributeSource atts) Construct the enumeration to be used, expanding the pattern term.inthashCode()Override and implement query hash code properly in a subclass.booleanIs this a binary (byte) oriented automaton.longReturn the memory usage of this object in bytes.Prints a query to a string, withfieldassumed to be the default field and omitted.voidvisit(QueryVisitor visitor) Recurse through the query tree, visiting any child queries.Methods inherited from class org.apache.lucene.search.MultiTermQuery
getField, getRewriteMethod, getTermsCount, getTermsEnum, rewriteMethods inherited from class org.apache.lucene.search.Query
classHash, createWeight, sameClassAs, toStringMethods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, waitMethods 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
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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.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, 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:MultiTermQueryConstruct 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.EMPTYif no terms match). The TermsEnum must already be positioned to the first matching term. The givenAttributeSourceis passed by theMultiTermQuery.RewriteMethodto share information between segments, for exampleTopTermsRewriteuses it to share maximum competitive boosts- Specified by:
getTermsEnumin classMultiTermQuery- Throws:
IOException
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hashCode
public int hashCode()Description copied from class:QueryOverride and implement query hash code properly in a subclass. This is required so thatQueryCacheworks properly.- Overrides:
hashCodein classMultiTermQuery- See Also:
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equals
Description copied from class:QueryOverride and implement query instance equivalence properly in a subclass. This is required so thatQueryCacheworks 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.
- Overrides:
equalsin classMultiTermQuery- See Also:
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toString
Description copied from class:QueryPrints a query to a string, withfieldassumed to be the default field and omitted. -
visit
Description copied from class:QueryRecurse through the query tree, visiting any child queries. -
getAutomaton
Returns the automaton used to create this query -
getCompiled
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isAutomatonBinary
public boolean isAutomatonBinary()Is this a binary (byte) oriented automaton. See the constructor. -
ramBytesUsed
public long ramBytesUsed()Description copied from interface:AccountableReturn the memory usage of this object in bytes. Negative values are illegal.- Specified by:
ramBytesUsedin interfaceAccountable
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