Package org.apache.lucene.analysis.icu

Class 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.

    • 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.