org.apache.lucene.analysis.en

Class KStemFilter

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.TokenFilter

org.apache.lucene.analysis.en.KStemFilter

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public final class KStemFilter
extends TokenFilter

A high-performance kstem filter for english.

See "Viewing Morphology as an Inference Process" (Krovetz, R., Proceedings of the Sixteenth Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, 191-203, 1993).

All terms must already be lowercased for this filter to work correctly.

Note: This filter is aware of the KeywordAttribute. To prevent certain terms from being passed to the stemmer KeywordAttribute.isKeyword() should be set to true in a previous TokenStream. Note: For including the original term as well as the stemmed version, see KeywordRepeatFilterFactory

Nested Class Summary

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

AttributeSource.State

Field Summary

Fields

Modifier and Type	Field and Description
private KeywordAttribute	keywordAtt
private KStemmer	stemmer
private CharTermAttribute	termAttribute

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
KStemFilter(TokenStream in)

Method Summary

Modifier and Type	Method and Description
boolean	incrementToken() Returns the next, stemmed, input Token.

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

Field Detail

stemmer

private final KStemmer stemmer

termAttribute

private final CharTermAttribute termAttribute

keywordAtt

private final KeywordAttribute keywordAtt

Constructor Detail

KStemFilter

public KStemFilter(TokenStream in)

Method Detail

incrementToken

public boolean incrementToken()
                       throws java.io.IOException

Returns the next, stemmed, input Token.

Specified by:

incrementToken in class TokenStream

Returns:

The stemmed form of a token.

Throws:

java.io.IOException - If there is a low-level I/O error.