Class AutomatonQuery
- java.lang.Object
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- org.apache.lucene.search.Query
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- org.apache.lucene.search.MultiTermQuery
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- org.apache.lucene.search.AutomatonQuery
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- All Implemented Interfaces:
Accountable
- Direct Known Subclasses:
PrefixQuery,RegexpQuery,TermRangeQuery,WildcardQuery
public class AutomatonQuery extends MultiTermQuery implements Accountable
AQuerythat 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.automatonAPI. Alternatively, it can be created from a regular expression withRegexpQueryor from the standard Lucene wildcard syntax withWildcardQuery.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
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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
Fields Modifier and Type Field Description protected Automatonautomatonthe automaton to match index terms againstprotected booleanautomatonIsBinaryprotected CompiledAutomatoncompiledprotected Termtermterm containing the field, and possibly some pattern structure-
Fields 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_REWRITE
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Fields inherited from interface org.apache.lucene.util.Accountable
NULL_ACCOUNTABLE
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Constructor Summary
Constructors Constructor Description AutomatonQuery(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
All Methods Instance Methods Concrete Methods Modifier and Type Method Description booleanequals(Object obj)Override and implement query instance equivalence properly in a subclass.AutomatongetAutomaton()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.booleanisAutomatonBinary()Is this a binary (byte) oriented automaton.longramBytesUsed()Return the memory usage of this object in bytes.StringtoString(String field)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, rewrite, setRewriteMethod
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Methods inherited from class org.apache.lucene.search.Query
classHash, createWeight, rewrite, sameClassAs, toString
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.apache.lucene.util.Accountable
getChildResources
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Field Detail
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automaton
protected final Automaton automaton
the automaton to match index terms against
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compiled
protected final CompiledAutomaton compiled
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term
protected final Term term
term containing the field, and possibly some pattern structure
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automatonIsBinary
protected final boolean automatonIsBinary
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Constructor Detail
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AutomatonQuery
public AutomatonQuery(Term term, Automaton automaton)
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
public AutomatonQuery(Term term, Automaton automaton, int determinizeWorkLimit)
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
public AutomatonQuery(Term term, Automaton automaton, int determinizeWorkLimit, boolean isBinary)
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 Detail
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getTermsEnum
protected TermsEnum getTermsEnum(Terms terms, AttributeSource atts) throws IOException
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:
Query.equals(Object)
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equals
public boolean equals(Object obj)
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:
Query.sameClassAs(Object),Query.classHash()
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toString
public String toString(String field)
Description copied from class:QueryPrints a query to a string, withfieldassumed to be the default field and omitted.
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visit
public void visit(QueryVisitor visitor)
Description copied from class:QueryRecurse through the query tree, visiting any child queries.
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getAutomaton
public Automaton getAutomaton()
Returns the automaton used to create this query
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isAutomatonBinary
public boolean isAutomatonBinary()
Is this a binary (byte) oriented automaton. See the constructor.
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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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