org.elasticsearch.index.analysis
Class ICUNormalizer2Filter

java.lang.Object
  org.apache.lucene.util.AttributeSource
      org.apache.lucene.analysis.TokenStream
          org.apache.lucene.analysis.TokenFilter
              org.elasticsearch.index.analysis.ICUNormalizer2Filter

All Implemented Interfaces:

java.io.Closeable

Direct Known Subclasses:

ICUFoldingFilter

public class ICUNormalizer2Filter
extends org.apache.lucene.analysis.TokenFilter

Normalize token text with ICU's Normalizer2

With this filter, you can normalize text in the following ways:

• NFKC Normalization, Case Folding, and removing Ignorables (the default)
• Using a standard Normalization mode (NFC, NFD, NFKC, NFKD)
• Based on rules from a custom normalization mapping.

If you use the defaults, this filter is a simple way to standardize Unicode text in a language-independent way for search:

• The case folding that it does can be seen as a replacement for LowerCaseFilter.
• Ignorables such as Zero-Width Joiner and Variation Selectors are removed. These are typically modifier characters that affect display.

See Also:

Normalizer2, FilteredNormalizer2

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

org.apache.lucene.util.AttributeSource.AttributeFactory, org.apache.lucene.util.AttributeSource.State

Field Summary

Fields inherited from class org.apache.lucene.analysis.TokenFilter

input

Constructor Summary

ICUNormalizer2Filter(org.apache.lucene.analysis.TokenStream input)
Create a new Normalizer2Filter that combines NFKC normalization, Case Folding, and removes Default Ignorables (NFKC_Casefold)

ICUNormalizer2Filter(org.apache.lucene.analysis.TokenStream input, com.ibm.icu.text.Normalizer2 normalizer)
Create a new Normalizer2Filter with the specified Normalizer2

Method Summary

boolean

incrementToken()

Methods inherited from class org.apache.lucene.analysis.TokenFilter

close, end, reset

Methods inherited from class org.apache.lucene.util.AttributeSource

addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, restoreState, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ICUNormalizer2Filter

public ICUNormalizer2Filter(org.apache.lucene.analysis.TokenStream input)

Create a new Normalizer2Filter that combines NFKC normalization, Case Folding, and removes Default Ignorables (NFKC_Casefold)

ICUNormalizer2Filter

public ICUNormalizer2Filter(org.apache.lucene.analysis.TokenStream input,
                            com.ibm.icu.text.Normalizer2 normalizer)

Create a new Normalizer2Filter with the specified Normalizer2

Parameters:

input - stream

normalizer - normalizer to use

Method Detail

incrementToken

public final boolean incrementToken()
                             throws java.io.IOException

Specified by:

incrementToken in class org.apache.lucene.analysis.TokenStream

Throws:

java.io.IOException