org.apache.lucene.analysis.ngram

Class NGramTokenizer

java.lang.Object

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.Tokenizer

org.apache.lucene.analysis.ngram.NGramTokenizer

public class NGramTokenizer
extends Tokenizer

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

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_MAX_NGRAM_SIZE
static int	DEFAULT_MIN_NGRAM_SIZE

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

input

Constructor Summary

Constructors

Constructor and Description
NGramTokenizer(Reader input) Creates NGramTokenizer with default min and max n-grams.
NGramTokenizer(Reader input, int minGram, int maxGram) Creates NGramTokenizer with given min and max n-grams.

Method Summary

Methods

Modifier and Type	Method and Description
Token	next(Token reusableToken) Returns the next token in the stream, or null at EOS.

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

close, reset

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

next, reset

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, 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

NGramTokenizer

public NGramTokenizer(Reader input,
              int minGram,
              int maxGram)

Creates NGramTokenizer with given min and max n-grams.

Parameters:

input - Reader holding the input to be tokenized

minGram - the smallest n-gram to generate

maxGram - the largest n-gram to generate

NGramTokenizer

public NGramTokenizer(Reader input)

Creates NGramTokenizer with default min and max n-grams.

Parameters:

input - Reader holding the input to be tokenized

Method Detail

next

public final Token next(Token reusableToken)
                 throws IOException

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

Overrides:

next in class TokenStream

Parameters:

reusableToken - a Token that may or may not be used to return; this parameter should never be null (the callee is not required to check for null before using it, but it is a good idea to assert that it is not null.)

Returns:

next token in the stream or null if end-of-stream was hit

Throws:

IOException