Package org.apache.lucene.search
Class NGramPhraseQuery
java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.search.NGramPhraseQuery
This is a
PhraseQuery
which is optimized for n-gram phrase query. For example, when you
query "ABCD" on a 2-gram field, you may want to use NGramPhraseQuery rather than PhraseQuery
, because NGramPhraseQuery will rewrite(IndexReader)
the query to "AB/0
CD/2", while PhraseQuery
will query "AB/0 BC/1 CD/2" (where term/position).-
Constructor Summary
ConstructorDescriptionNGramPhraseQuery
(int n, PhraseQuery query) Constructor that takes gram size. -
Method Summary
Modifier and TypeMethodDescriptionboolean
Override and implement query instance equivalence properly in a subclass.int
getN()
Return the n in n-gramint[]
Return the list of relative positions that each term should appear at.Term[]
getTerms()
Return the list of terms.int
hashCode()
Override and implement query hash code properly in a subclass.rewrite
(IndexReader reader) Expert: called to re-write queries into primitive queries.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.Query
classHash, createWeight, sameClassAs, toString
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Constructor Details
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NGramPhraseQuery
Constructor that takes gram size.- Parameters:
n
- n-gram size
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Method Details
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rewrite
Description copied from class:Query
Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.- Overrides:
rewrite
in classQuery
- Throws:
IOException
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visit
Description copied from class:Query
Recurse through the query tree, visiting any child queries -
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.
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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. -
getN
public int getN()Return the n in n-gram -
getTerms
Return the list of terms. -
getPositions
public int[] getPositions()Return the list of relative positions that each term should appear at. -
toString
Description copied from class:Query
Prints a query to a string, withfield
assumed to be the default field and omitted.
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