Class ICUCollationKeyAnalyzer

Configures Lucene.Net.Analysis.Core.KeywordTokenizer with ICUCollationAttributeFactory.

Inheritance
System.Object
Lucene.Net.Analysis.Analyzer
ICUCollationKeyAnalyzer
Implements
System.IDisposable
Inherited Members
Lucene.Net.Analysis.Analyzer.Strategy
Lucene.Net.Analysis.Analyzer.Dispose()
Lucene.Net.Analysis.Analyzer.GLOBAL_REUSE_STRATEGY
Lucene.Net.Analysis.Analyzer.PER_FIELD_REUSE_STRATEGY
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.ToString()
Namespace: Lucene.Net.Collation
Assembly: Lucene.Net.ICU.dll
Syntax
public sealed class ICUCollationKeyAnalyzer : Analyzer, IDisposable
Remarks

Converts the token into its ICU4N.Text.CollationKey, and then encodes the ICU4N.Text.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 ICU4N.Text.Collator at index and query time -- CollationKeys are only comparable when produced by the same ICU4N.Text.Collator. ICU4N.Text.RuleBasedCollators are independently versioned, so it is safe to search against stored ICU4N.Text.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):

  1. Collator version - see ICU4N.Text.Collator Version
  2. The collation strength used - see ICU4N.Text.Collator.Strength

ICU4N.Text.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.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating ICUCollationKeyAnalyzer:

  • As of 4.0, ICU4N.Text.CollationKeys are directly encoded as bytes. Previous versions will encode the bytes with IndexableBinaryStringTools.

Constructors

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ICUCollationKeyAnalyzer(Collator)

Declaration
[Obsolete("Use ICUCollationKeyAnalyzer.ICUCollationKeyAnalyzer(LuceneVersion, Collator) and specify a version instead. This ctor will be removed in Lucene 5.0")]
public ICUCollationKeyAnalyzer(Collator collator)
Parameters
Type Name Description
ICU4N.Text.Collator collator
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ICUCollationKeyAnalyzer(LuceneVersion, Collator)

Create a new ICUCollationKeyAnalyzer, using the specified collator.

Declaration
public ICUCollationKeyAnalyzer(LuceneVersion matchVersion, Collator collator)
Parameters
Type Name Description
Lucene.Net.Util.LuceneVersion matchVersion

See ICUCollationKeyAnalyzer.
ICU4N.Text.Collator collator

ICU4N.Text.CollationKey generator.

Methods

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CreateComponents(String, TextReader)

Declaration
protected override TokenStreamComponents CreateComponents(string fieldName, TextReader reader)
Parameters
Type Name Description
System.String fieldName
System.IO.TextReader reader
Returns
Type Description
Lucene.Net.Analysis.TokenStreamComponents
Overrides

Implements

System.IDisposable