Class CollationKeyFilter
- 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.collation.CollationKeyFilter
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
@Deprecated public final class CollationKeyFilter extends TokenFilter
Deprecated.UseCollationAttributeFactory
instead, which encodes terms directly as bytes. This filter will be removed in Lucene 5.0Converts each token into its
CollationKey
, and then encodes the CollationKey withIndexableBinaryStringTools
, to allow it to be stored as an index term.WARNING: Make sure you use exactly the same Collator at index and query time -- CollationKeys are only comparable when produced by the same Collator. Since
RuleBasedCollator
s are not independently versioned, it is unsafe to search against stored CollationKeys unless the following are exactly the same (best practice is to store this information with the index and check that they remain the same at query time):- JVM vendor
- JVM version, including patch version
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The language (and country and variant, if specified) of the Locale
used when constructing the collator via
Collator.getInstance(java.util.Locale)
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The collation strength used - see
Collator.setStrength(int)
The
ICUCollationKeyFilter
in the analysis-icu package uses ICU4J's Collator, which makes its version available, thus allowing collation to be versioned independently from the JVM. ICUCollationKeyFilter is also significantly faster and generates significantly shorter keys than CollationKeyFilter. See http://site.icu-project.org/charts/collation-icu4j-sun for key generation timing and key length comparisons between ICU4J and java.text.Collator over several languages.CollationKeys generated by java.text.Collators are not compatible with those those generated by ICU Collators. Specifically, if you use CollationKeyFilter to generate index terms, do not use ICUCollationKeyFilter on the query side, or vice versa.
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.AttributeFactory, AttributeSource.State
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Constructor Summary
Constructors Constructor Description CollationKeyFilter(TokenStream input, java.text.Collator collator)
Deprecated.
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description boolean
incrementToken()
Deprecated.Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token.-
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, reset
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Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, restoreState, toString
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Constructor Detail
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CollationKeyFilter
public CollationKeyFilter(TokenStream input, java.text.Collator collator)
Deprecated.- Parameters:
input
- Source token streamcollator
- CollationKey generator
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Method Detail
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incrementToken
public boolean incrementToken() throws java.io.IOException
Deprecated.Description copied from class:TokenStream
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriateAttributeImpl
s with the attributes of the next token.The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState()
to create a copy of the current attribute state.This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to
AttributeSource.addAttribute(Class)
andAttributeSource.getAttribute(Class)
, references to allAttributeImpl
s that this stream uses should be retrieved during instantiation.To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in
TokenStream.incrementToken()
.- Specified by:
incrementToken
in classTokenStream
- Returns:
- false for end of stream; true otherwise
- Throws:
java.io.IOException
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