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