Class ICUCollationAttributeFactory

Converts each token into its ICU4N.Text.CollationKey, and then encodes bytes as an index term.

Inheritance

System.Object

Lucene.Net.Util.AttributeSource.AttributeFactory

ICUCollationAttributeFactory

Inherited Members

Lucene.Net.Util.AttributeSource.AttributeFactory.DEFAULT_ATTRIBUTE_FACTORY

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 class ICUCollationAttributeFactory : AttributeSource.AttributeFactory

Remarks

WARNING: Make sure you use exactly the same ICU4N.Text.Collator at index and query time -- ICU4N.Text.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 ICUCollationAttributeFactory to generate index terms, do not use CollationAttributeFactory on the query side, or vice versa.

ICUCollationAttributeFactory is significantly faster and generates significantly shorter keys than CollationAttributeFactory. 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.

Constructors

ICUCollationAttributeFactory(Collator)

Create an ICUCollationAttributeFactory, using Lucene.Net.Util.AttributeSource.AttributeFactory.DEFAULT_ATTRIBUTE_FACTORY as the factory for all other attributes.

Declaration

public ICUCollationAttributeFactory(Collator collator)

Parameters

Type	Name	Description
ICU4N.Text.Collator	collator	ICU4N.Text.CollationKey generator

ICUCollationAttributeFactory(AttributeSource.AttributeFactory, Collator)

Create an ICUCollationAttributeFactory, using the supplied Attribute Factory as the factory for all other attributes.

Declaration

public ICUCollationAttributeFactory(AttributeSource.AttributeFactory delegate, Collator collator)

Parameters

Type	Name	Description
Lucene.Net.Util.AttributeSource.AttributeFactory	delegate	Attribute Factory
ICU4N.Text.Collator	collator	ICU4N.Text.CollationKey generator

Methods

CreateAttributeInstance<T>()

Declaration

public override Attribute CreateAttributeInstance<T>()
    where T : IAttribute

Returns

Type	Description
Lucene.Net.Util.Attribute

Type Parameters

Name	Description
T

Overrides

Lucene.Net.Util.AttributeSource.AttributeFactory.CreateAttributeInstance<T>()