Package org.apache.lucene.analysis.ko

Class KoreanTokenizer

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.Tokenizer

org.apache.lucene.analysis.ko.KoreanTokenizer

All Implemented Interfaces:

Closeable, AutoCloseable

public final class KoreanTokenizer
extends Tokenizer

Tokenizer for Korean that uses morphological analysis.

This tokenizer sets a number of additional attributes:

• PartOfSpeechAttribute containing part-of-speech.
• ReadingAttribute containing reading.

This tokenizer uses a rolling Viterbi search to find the least cost segmentation (path) of the incoming characters.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	KoreanTokenizer.DecompoundMode	Decompound mode: this determines how the tokenizer handles POS.Type.COMPOUND, POS.Type.INFLECT and POS.Type.PREANALYSIS tokens.
static enum	KoreanTokenizer.Type	Token type reflecting the original source of this token

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

AttributeSource.State

Field Summary

Fields

Modifier and Type	Field	Description
static final KoreanTokenizer.DecompoundMode	DEFAULT_DECOMPOUND	Default mode for the decompound of tokens (KoreanTokenizer.DecompoundMode.DISCARD.

Fields inherited from class org.apache.lucene.analysis.Tokenizer

input

Fields inherited from class org.apache.lucene.analysis.TokenStream

DEFAULT_TOKEN_ATTRIBUTE_FACTORY

Constructor Summary

Constructors

Constructor	Description
KoreanTokenizer()	Creates a new KoreanTokenizer with default parameters.
KoreanTokenizer(AttributeFactory factory, TokenInfoDictionary systemDictionary, UnknownDictionary unkDictionary, ConnectionCosts connectionCosts, UserDictionary userDictionary, KoreanTokenizer.DecompoundMode mode, boolean outputUnknownUnigrams, boolean discardPunctuation)	Create a new KoreanTokenizer supplying a custom system dictionary and unknown dictionary.
KoreanTokenizer(AttributeFactory factory, UserDictionary userDictionary, KoreanTokenizer.DecompoundMode mode, boolean outputUnknownUnigrams)	Create a new KoreanTokenizer using the system and unknown dictionaries shipped with Lucene.
KoreanTokenizer(AttributeFactory factory, UserDictionary userDictionary, KoreanTokenizer.DecompoundMode mode, boolean outputUnknownUnigrams, boolean discardPunctuation)	Create a new KoreanTokenizer using the system and unknown dictionaries shipped with Lucene.

Method Summary

Modifier and Type	Method	Description
void	close()
void	end()
boolean	incrementToken()
void	reset()
void	setGraphvizFormatter(GraphvizFormatter dotOut)	Expert: set this to produce graphviz (dot) output of the Viterbi lattice

Methods inherited from class org.apache.lucene.analysis.Tokenizer

correctOffset, setReader, setReaderTestPoint

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_DECOMPOUND

public static final KoreanTokenizer.DecompoundMode DEFAULT_DECOMPOUND

Default mode for the decompound of tokens (KoreanTokenizer.DecompoundMode.DISCARD.

Constructor Details

KoreanTokenizer

public KoreanTokenizer()

Creates a new KoreanTokenizer with default parameters.

Uses the default AttributeFactory.

KoreanTokenizer

public KoreanTokenizer(AttributeFactory factory,
 UserDictionary userDictionary,
 KoreanTokenizer.DecompoundMode mode,
 boolean outputUnknownUnigrams)

Create a new KoreanTokenizer using the system and unknown dictionaries shipped with Lucene.

Parameters:

factory - the AttributeFactory to use

userDictionary - Optional: if non-null, user dictionary.

mode - Decompound mode.

outputUnknownUnigrams - if true outputs unigrams for unknown words.

KoreanTokenizer

public KoreanTokenizer(AttributeFactory factory,
 UserDictionary userDictionary,
 KoreanTokenizer.DecompoundMode mode,
 boolean outputUnknownUnigrams,
 boolean discardPunctuation)

Create a new KoreanTokenizer using the system and unknown dictionaries shipped with Lucene.

Parameters:

factory - the AttributeFactory to use

userDictionary - Optional: if non-null, user dictionary.

mode - Decompound mode.

outputUnknownUnigrams - if true outputs unigrams for unknown words.

discardPunctuation - true if punctuation tokens should be dropped from the output.

KoreanTokenizer

public KoreanTokenizer(AttributeFactory factory,
 TokenInfoDictionary systemDictionary,
 UnknownDictionary unkDictionary,
 ConnectionCosts connectionCosts,
 UserDictionary userDictionary,
 KoreanTokenizer.DecompoundMode mode,
 boolean outputUnknownUnigrams,
 boolean discardPunctuation)

Create a new KoreanTokenizer supplying a custom system dictionary and unknown dictionary. This constructor provides an entry point for users that want to construct custom language models that can be used as input to DictionaryBuilder.

Parameters:

factory - the AttributeFactory to use

systemDictionary - a custom known token dictionary

unkDictionary - a custom unknown token dictionary

connectionCosts - custom token transition costs

userDictionary - Optional: if non-null, user dictionary.

mode - Decompound mode.

outputUnknownUnigrams - if true outputs unigrams for unknown words.

discardPunctuation - true if punctuation tokens should be dropped from the output.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Method Details

setGraphvizFormatter

public void setGraphvizFormatter(GraphvizFormatter dotOut)

Expert: set this to produce graphviz (dot) output of the Viterbi lattice

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class Tokenizer

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class Tokenizer

Throws:

IOException

end

public void end()
         throws IOException

Overrides:

end in class TokenStream

Throws:

IOException

incrementToken

public boolean incrementToken()
                       throws IOException

Specified by:

incrementToken in class TokenStream

Throws:

IOException