org.apache.lucene.analysis.icu

## Class ICUTransformFilter

- java.lang.Object
- - org.apache.lucene.util.AttributeSource
  - - org.apache.lucene.analysis.TokenStream
    - - org.apache.lucene.analysis.TokenFilter
      - - org.apache.lucene.analysis.icu.ICUTransformFilter

- All Implemented Interfaces:
    Closeable, AutoCloseable

      public final class ICUTransformFilter
      extends TokenFilter

  A `TokenFilter` that transforms text with ICU.

  ICU provides text-transformation functionality via its Transliteration API. Although script conversion is its most common use, a Transliterator can actually perform a more general class of tasks. In fact, Transliterator defines a very general API which specifies only that a segment of the input text is replaced by new text. The particulars of this conversion are determined entirely by subclasses of Transliterator.

  Some useful transformations for search are built-in:

  - Conversion from Traditional to Simplified Chinese characters
  - Conversion from Hiragana to Katakana
  - Conversion from Fullwidth to Halfwidth forms.
  - Script conversions, for example Serbian Cyrillic to Latin

  Example usage:

  > stream = new ICUTransformFilter(stream, Transliterator.getInstance("Traditional-Simplified"));

  For more details, see the ICU User Guide.

- - ### Nested Class Summary

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

      `AttributeSource.State`

  - ### Field Summary

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

      `input`

    - ### Fields inherited from class org.apache.lucene.analysis.TokenStream

      `DEFAULT_TOKEN_ATTRIBUTE_FACTORY`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `ICUTransformFilter(TokenStream input, com.ibm.icu.text.Transliterator transform)` Create a new ICUTransformFilter that transforms text on the given stream.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `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, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString`

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### ICUTransformFilter

          public ICUTransformFilter(TokenStream input,
                                    com.ibm.icu.text.Transliterator transform)

      Create a new ICUTransformFilter that transforms text on the given stream.
      Parameters:
        `input` - `TokenStream` to filter.
        `transform` - Transliterator to transform the text.

  - ### Method Detail

    - #### incrementToken

          public boolean incrementToken()
                                 throws IOException

      Specified by:
        `incrementToken` in class `TokenStream`
      Throws:
        `IOException`

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