Module org.apache.lucene.analysis.kuromoji

Package org.apache.lucene.analysis.ja

Class JapaneseReadingFormFilter

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.TokenFilter

org.apache.lucene.analysis.ja.JapaneseReadingFormFilter

All Implemented Interfaces:

Closeable, AutoCloseable, Unwrappable<TokenStream>

public final class JapaneseReadingFormFilter
extends TokenFilter

A TokenFilter that replaces the term attribute with the reading of a token in either katakana or romaji form. The default reading form is katakana.

Nested Class Summary

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

AttributeSource.State

Field Summary

Fields

Modifier and Type	Field	Description
private StringBuilder	buffer
private static final char	HIRAGANA_END
private static final char	HIRAGANA_START
private final ReadingAttribute	readingAttr
private final CharTermAttribute	termAttr
private boolean	useRomaji

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
JapaneseReadingFormFilter(TokenStream input)
JapaneseReadingFormFilter(TokenStream input, boolean useRomaji)

Method Summary

Modifier and Type	Method	Description
private boolean	containsHiragana(CharSequence s)
boolean	incrementToken()	Consumers (i.e., IndexWriter) use this method to advance the stream to the next token.
private boolean	isHiragana(char ch)

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

termAttr

private final CharTermAttribute termAttr

readingAttr

private final ReadingAttribute readingAttr

buffer

private StringBuilder buffer

useRomaji

private boolean useRomaji

HIRAGANA_START

private static final char HIRAGANA_START

See Also:

• Constant Field Values

HIRAGANA_END

private static final char HIRAGANA_END

See Also:

• Constant Field Values

Constructor Details

JapaneseReadingFormFilter

public JapaneseReadingFormFilter(TokenStream input,
 boolean useRomaji)

JapaneseReadingFormFilter

public JapaneseReadingFormFilter(TokenStream input)

Method Details

isHiragana

private boolean isHiragana(char ch)

containsHiragana

private boolean containsHiragana(CharSequence s)

incrementToken

public boolean incrementToken()
                       throws IOException

Description copied from class: TokenStream

Consumers (i.e., IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate AttributeImpls with the attributes of the next token.

The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use AttributeSource.captureState() to create a copy of the current attribute state.

This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to AttributeSource.addAttribute(Class) and AttributeSource.getAttribute(Class), references to all AttributeImpls that this stream uses should be retrieved during instantiation.

To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in TokenStream.incrementToken().

Specified by:

incrementToken in class TokenStream

Returns:

false for end of stream; true otherwise

Throws:

IOException