org.apache.lucene.analysis.ngram

Class EdgeNGramTokenFilter

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.TokenFilter

org.apache.lucene.analysis.ngram.EdgeNGramTokenFilter

All Implemented Interfaces:

Closeable, AutoCloseable

public final class EdgeNGramTokenFilter
extends TokenFilter

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

This TokenFilter create n-grams from the beginning edge of a input token.

As of Lucene 4.4, this filter handles correctly supplementary characters.

Nested Class Summary

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

AttributeSource.State

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_MAX_GRAM_SIZE
static int	DEFAULT_MIN_GRAM_SIZE

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 and Description
EdgeNGramTokenFilter(TokenStream input, int minGram, int maxGram) Creates EdgeNGramTokenFilter that can generate n-grams in the sizes of the given range

Method Summary

Methods

Modifier and Type	Method and Description
boolean	incrementToken()
void	reset()

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, removeAllAttributes, restoreState, toString

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MAX_GRAM_SIZE

public static final int DEFAULT_MAX_GRAM_SIZE

See Also:

Constant Field Values

DEFAULT_MIN_GRAM_SIZE

public static final int DEFAULT_MIN_GRAM_SIZE

See Also:

Constant Field Values

Constructor Detail

EdgeNGramTokenFilter

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

Creates EdgeNGramTokenFilter that can generate n-grams in the sizes of the given range

Parameters:

input - TokenStream holding the input to be tokenized

minGram - the smallest n-gram to generate

maxGram - the largest n-gram to generate

Method Detail

incrementToken

public final boolean incrementToken()
                             throws IOException

Specified by:

incrementToken in class TokenStream

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class TokenFilter

Throws:

IOException