org.apache.lucene.analysis.cjk
Class CJKTokenizer

java.lang.Object
  org.apache.lucene.util.AttributeSource
      org.apache.lucene.analysis.TokenStream
          org.apache.lucene.analysis.Tokenizer
              org.apache.lucene.analysis.cjk.CJKTokenizer

public final class CJKTokenizer
extends org.apache.lucene.analysis.Tokenizer

CJKTokenizer is designed for Chinese, Japanese, and Korean languages.

The tokens returned are every two adjacent characters with overlap match.

Example: "java C1C2C3C4" will be segmented to: "java" "C1C2" "C2C3" "C3C4".

Additionally, the following is applied to Latin text (such as English):

• Text is converted to lowercase.
• Numeric digits, '+', '#', and '_' are tokenized as letters.
• Full-width forms are converted to half-width forms.

For more info on Asian language (Chinese, Japanese, and Korean) text segmentation: please search google

Nested Class Summary

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

org.apache.lucene.util.AttributeSource.AttributeFactory, org.apache.lucene.util.AttributeSource.State

Field Summary

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

input

Constructor Summary

CJKTokenizer(org.apache.lucene.util.AttributeSource.AttributeFactory factory, Reader in)

CJKTokenizer(org.apache.lucene.util.AttributeSource source, Reader in)

CJKTokenizer(Reader in)
Construct a token stream processing the given input.

Method Summary

void	end()
boolean	incrementToken() Returns true for the next token in the stream, or false at EOS.
void	reset()
void	reset(Reader reader)

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

close, correctOffset

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

getOnlyUseNewAPI, next, next, setOnlyUseNewAPI

Methods inherited from class org.apache.lucene.util.AttributeSource

addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, restoreState, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

CJKTokenizer

public CJKTokenizer(Reader in)

Construct a token stream processing the given input.

Parameters:

in - I/O reader

CJKTokenizer

public CJKTokenizer(org.apache.lucene.util.AttributeSource source,
                    Reader in)

CJKTokenizer

public CJKTokenizer(org.apache.lucene.util.AttributeSource.AttributeFactory factory,
                    Reader in)

Method Detail

incrementToken

public boolean incrementToken()
                       throws IOException

Returns true for the next token in the stream, or false at EOS. See http://java.sun.com/j2se/1.3/docs/api/java/lang/Character.UnicodeBlock.html for detail.

Overrides:

incrementToken in class org.apache.lucene.analysis.TokenStream

Returns:

false for end of stream, true otherwise

Throws:

IOException - - throw IOException when read error
happened in the InputStream

end

public final void end()

Overrides:

end in class org.apache.lucene.analysis.TokenStream

reset

public void reset()
           throws IOException

Overrides:

reset in class org.apache.lucene.analysis.TokenStream

Throws:

IOException

reset

public void reset(Reader reader)
           throws IOException

Overrides:

reset in class org.apache.lucene.analysis.Tokenizer

Throws:

IOException