Class ICUCollationKeyAnalyzer
- java.lang.Object
-
- org.apache.lucene.analysis.Analyzer
-
- org.apache.lucene.collation.ICUCollationKeyAnalyzer
-
- All Implemented Interfaces:
Closeable
,AutoCloseable
public final class ICUCollationKeyAnalyzer extends org.apache.lucene.analysis.Analyzer
Filters
KeywordTokenizer
withICUCollationKeyFilter
.Converts the 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.
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 version - see
Collator.getVersion()
-
The collation strength used - see
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 Summary
Constructors Constructor Description ICUCollationKeyAnalyzer(com.ibm.icu.text.Collator collator)
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description org.apache.lucene.analysis.TokenStream
reusableTokenStream(String fieldName, Reader reader)
org.apache.lucene.analysis.TokenStream
tokenStream(String fieldName, Reader reader)
-
-
-
Method Detail
-
tokenStream
public org.apache.lucene.analysis.TokenStream tokenStream(String fieldName, Reader reader)
- Specified by:
tokenStream
in classorg.apache.lucene.analysis.Analyzer
-
reusableTokenStream
public org.apache.lucene.analysis.TokenStream reusableTokenStream(String fieldName, Reader reader) throws IOException
- Overrides:
reusableTokenStream
in classorg.apache.lucene.analysis.Analyzer
- Throws:
IOException
-
-