org.apache.lucene.analysis.ngram
Class NGramTokenFilter

java.lang.Object
  org.apache.lucene.util.AttributeSource
      org.apache.lucene.analysis.TokenStream
          org.apache.lucene.analysis.TokenFilter
              org.apache.lucene.analysis.ngram.NGramTokenFilter

All Implemented Interfaces:

Closeable

public final class NGramTokenFilter
extends TokenFilter

Tokenizes the input into n-grams of the given size(s).

Nested Class Summary

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

AttributeSource.AttributeFactory, AttributeSource.State

Field Summary

static int	DEFAULT_MAX_NGRAM_SIZE
static int	DEFAULT_MIN_NGRAM_SIZE

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

input

Constructor Summary

NGramTokenFilter(TokenStream input)
Creates NGramTokenFilter with default min and max n-grams.

NGramTokenFilter(TokenStream input, int minGram, int maxGram)
Creates NGramTokenFilter with given min and max n-grams.

Method Summary

boolean	incrementToken() Returns the next token in the stream, or null at EOS.
void	reset() Reset the filter as well as the input TokenStream.

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

close, end

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

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

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MIN_NGRAM_SIZE

public static final int DEFAULT_MIN_NGRAM_SIZE

See Also:

Constant Field Values

DEFAULT_MAX_NGRAM_SIZE

public static final int DEFAULT_MAX_NGRAM_SIZE

See Also:

Constant Field Values

Constructor Detail

NGramTokenFilter

public NGramTokenFilter(TokenStream input,
                        int minGram,
                        int maxGram)

Creates NGramTokenFilter with given min and max n-grams.

Parameters:

input - TokenStream holding the input to be tokenized

minGram - the smallest n-gram to generate

maxGram - the largest n-gram to generate

NGramTokenFilter

public NGramTokenFilter(TokenStream input)

Creates NGramTokenFilter with default min and max n-grams.

Parameters:

input - TokenStream holding the input to be tokenized

Method Detail

incrementToken

public final boolean incrementToken()
                             throws IOException

Returns the next token in the stream, or null at EOS.

Specified by:

incrementToken in class TokenStream

Returns:

false for end of stream; true otherwise

Throws:

IOException

reset

public void reset()
           throws IOException

Description copied from class: TokenFilter

Reset the filter as well as the input TokenStream.

Overrides:

reset in class TokenFilter

Throws:

IOException