Package org.apache.lucene.analysis.ja

# Class JapaneseKatakanaStemFilter

java.lang.Object
org.apache.lucene.util.AttributeSource
org.apache.lucene.analysis.TokenStream
org.apache.lucene.analysis.TokenFilter
org.apache.lucene.analysis.ja.JapaneseKatakanaStemFilter

All Implemented Interfaces:
  `Closeable`, `AutoCloseable`, `Unwrappable<TokenStream>`

public final class JapaneseKatakanaStemFilter extends TokenFilter
A `TokenFilter` that normalizes common katakana spelling variations ending in a long sound character by removing this character (U+30FC). Only katakana words longer than a minimum length are stemmed (default is four).

Note that only full-width katakana characters are supported. Please use a `CJKWidthFilter` to convert half-width katakana to full-width before using this filter.

In order to prevent terms from being stemmed, use an instance of `SetKeywordMarkerFilter` or a custom `TokenFilter` that sets the `KeywordAttribute` before this `TokenStream`.

- ## Nested Class Summary

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

  `AttributeSource.State`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final int`
  `DEFAULT_MINIMUM_LENGTH`

  ### 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
  Description
  `JapaneseKatakanaStemFilter(TokenStream input)`
  `JapaneseKatakanaStemFilter(TokenStream input, int minimumLength)`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `boolean`
  `incrementToken()`

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

  `close, end, reset, unwrap`

  ### 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`

- ## Field Details

  - ### DEFAULT_MINIMUM_LENGTH

    public static final int DEFAULT_MINIMUM_LENGTH
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### JapaneseKatakanaStemFilter

    public JapaneseKatakanaStemFilter(TokenStream input, int minimumLength)

  - ### JapaneseKatakanaStemFilter

    public JapaneseKatakanaStemFilter(TokenStream input)

- ## Method Details

  - ### incrementToken

    public boolean incrementToken() throws IOException
    Specified by:
      `incrementToken` in class `TokenStream`
    Throws:
      `IOException`