Class CommonGramsQueryFilter
- java.lang.Object
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- org.apache.lucene.util.AttributeSource
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- org.apache.lucene.analysis.TokenStream
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- org.apache.lucene.analysis.TokenFilter
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- org.apache.lucene.analysis.commongrams.CommonGramsQueryFilter
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- All Implemented Interfaces:
Closeable
,AutoCloseable
public final class CommonGramsQueryFilter extends TokenFilter
Wrap a CommonGramsFilter optimizing phrase queries by only returning single words when they are not a member of a bigram.Example:
- query input to CommonGramsFilter: "the rain in spain falls mainly"
- output of CommomGramsFilter/input to CommonGramsQueryFilter: |"the, "the-rain"|"rain" "rain-in"|"in, "in-spain"|"spain"|"falls"|"mainly"
- output of CommonGramsQueryFilter:"the-rain", "rain-in" ,"in-spain", "falls", "mainly"
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
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Field Summary
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Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
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Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
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Constructor Summary
Constructors Constructor Description CommonGramsQueryFilter(CommonGramsFilter input)
Constructs a new CommonGramsQueryFilter based on the provided CommomGramsFilter
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
incrementToken()
Output bigrams whenever possible to optimize queries.boolean
isGramType()
Convenience method to check if the current type is a gram typevoid
reset()
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Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end
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Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
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Constructor Detail
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CommonGramsQueryFilter
public CommonGramsQueryFilter(CommonGramsFilter input)
Constructs a new CommonGramsQueryFilter based on the provided CommomGramsFilter- Parameters:
input
- CommonGramsFilter the QueryFilter will use
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Method Detail
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reset
public void reset() throws IOException
- Overrides:
reset
in classTokenFilter
- Throws:
IOException
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incrementToken
public boolean incrementToken() throws IOException
Output bigrams whenever possible to optimize queries. Only output unigrams when they are not a member of a bigram. Example:- input: "the rain in spain falls mainly"
- output:"the-rain", "rain-in" ,"in-spain", "falls", "mainly"
- Specified by:
incrementToken
in classTokenStream
- Throws:
IOException
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isGramType
public boolean isGramType()
Convenience method to check if the current type is a gram type- Returns:
true
if the current type is a gram type,false
otherwise
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