org.apache.lucene.collation
Class CollationKeyFilter
java.lang.Object
org.apache.lucene.util.AttributeSource
org.apache.lucene.analysis.TokenStream
org.apache.lucene.analysis.TokenFilter
org.apache.lucene.collation.CollationKeyFilter
- All Implemented Interfaces:
- Closeable
Deprecated. Use CollationAttributeFactory
instead, which encodes
terms directly as bytes. This filter will be removed in Lucene 5.0
@Deprecated
public final class CollationKeyFilter
- extends TokenFilter
Converts each token into its CollationKey
, and then
encodes the CollationKey with IndexableBinaryStringTools
, 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
-
The language (and country and variant, if specified) of the Locale
used when constructing the collator via
Collator.getInstance(java.util.Locale)
.
-
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.
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 |
CollationKeyFilter
public CollationKeyFilter(TokenStream input,
Collator collator)
- Deprecated.
- Parameters:
input
- Source token streamcollator
- CollationKey generator
incrementToken
public boolean incrementToken()
throws IOException
- Deprecated.
- Specified by:
incrementToken
in class TokenStream
- Throws:
IOException
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