public final class CollationKeyAnalyzer extends Analyzer
Configures KeywordTokenizer
with CollationAttributeFactory
.
Converts the token into its CollationKey
, and then
encodes the CollationKey either directly or with
IndexableBinaryStringTools
(see below), 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):
Collator.getInstance(java.util.Locale)
.
Collator.setStrength(int)
The ICUCollationKeyAnalyzer
in the analysis-icu package
uses ICU4J's Collator, which makes its
its version available, thus allowing collation to be versioned
independently from the JVM. ICUCollationKeyAnalyzer is also significantly
faster and generates significantly shorter keys than CollationKeyAnalyzer.
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 CollationKeyAnalyzer to generate index terms, do not use ICUCollationKeyAnalyzer on the query side, or vice versa.
You must specify the required Version
compatibility when creating CollationKeyAnalyzer:
IndexableBinaryStringTools
.
Analyzer.GlobalReuseStrategy, Analyzer.PerFieldReuseStrategy, Analyzer.ReuseStrategy, Analyzer.TokenStreamComponents
GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY
Constructor and Description |
---|
CollationKeyAnalyzer(Collator collator)
Deprecated.
Use
CollationKeyAnalyzer(Version, Collator)
and specify a version instead. This ctor will be removed in Lucene 5.0 |
CollationKeyAnalyzer(Version matchVersion,
Collator collator)
Create a new CollationKeyAnalyzer, using the specified collator.
|
Modifier and Type | Method and Description |
---|---|
protected Analyzer.TokenStreamComponents |
createComponents(String fieldName,
Reader reader) |
close, getOffsetGap, getPositionIncrementGap, getReuseStrategy, initReader, tokenStream, tokenStream
public CollationKeyAnalyzer(Version matchVersion, Collator collator)
matchVersion
- See abovecollator
- CollationKey generator@Deprecated public CollationKeyAnalyzer(Collator collator)
CollationKeyAnalyzer(Version, Collator)
and specify a version instead. This ctor will be removed in Lucene 5.0protected Analyzer.TokenStreamComponents createComponents(String fieldName, Reader reader)
createComponents
in class Analyzer
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