public final class ICUCollationKeyAnalyzer
extends org.apache.lucene.analysis.Analyzer
Filters KeywordTokenizer
with ICUCollationKeyFilter
.
Converts the 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. RuleBasedCollator
s are
independently versioned, so it is safe to search against stored
CollationKeys if 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.getVersion()
Collator.setStrength(int)
CollationKeys generated by ICU Collators are not compatible with those
generated by java.text.Collators. Specifically, if you use
ICUCollationKeyAnalyzer to generate index terms, do not use
CollationKeyAnalyzer
on the query side, or vice versa.
ICUCollationKeyAnalyzer is 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.
Constructor and Description |
---|
ICUCollationKeyAnalyzer(com.ibm.icu.text.Collator collator) |
Modifier and Type | Method and Description |
---|---|
org.apache.lucene.analysis.TokenStream |
reusableTokenStream(String fieldName,
Reader reader) |
org.apache.lucene.analysis.TokenStream |
tokenStream(String fieldName,
Reader reader) |
public ICUCollationKeyAnalyzer(com.ibm.icu.text.Collator collator)
public org.apache.lucene.analysis.TokenStream tokenStream(String fieldName, Reader reader)
tokenStream
in class org.apache.lucene.analysis.Analyzer
public org.apache.lucene.analysis.TokenStream reusableTokenStream(String fieldName, Reader reader) throws IOException
reusableTokenStream
in class org.apache.lucene.analysis.Analyzer
IOException