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

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 or ending edge of a input token.

As of Lucene 4.4, this filter does not support EdgeNGramTokenFilter.Side.BACK (you can use ReverseStringFilter up-front and afterward to get the same behavior), handles supplementary characters correctly and does not update offsets anymore.

Nested Class Summary

static class

EdgeNGramTokenFilter.Side Specifies which side of the input the n-gram should be generated from

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

AttributeSource.AttributeFactory, AttributeSource.State

Field Summary

static int	DEFAULT_MAX_GRAM_SIZE
static int	DEFAULT_MIN_GRAM_SIZE
static EdgeNGramTokenFilter.Side	DEFAULT_SIDE

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

input

Constructor Summary

EdgeNGramTokenFilter(Version version, TokenStream input, EdgeNGramTokenFilter.Side side, int minGram, int maxGram)
Deprecated.

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

EdgeNGramTokenFilter(Version version, TokenStream input, String sideLabel, int minGram, int maxGram)
Deprecated.

Method Summary

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, restoreState, toString

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_SIDE

public static final EdgeNGramTokenFilter.Side DEFAULT_SIDE

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

@Deprecated
public EdgeNGramTokenFilter(Version version,
                                       TokenStream input,
                                       EdgeNGramTokenFilter.Side side,
                                       int minGram,
                                       int maxGram)

Deprecated.

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

Parameters:

version - the Lucene match version

input - TokenStream holding the input to be tokenized

side - the EdgeNGramTokenFilter.Side from which to chop off an n-gram

minGram - the smallest n-gram to generate

maxGram - the largest n-gram to generate

EdgeNGramTokenFilter

@Deprecated
public EdgeNGramTokenFilter(Version version,
                                       TokenStream input,
                                       String sideLabel,
                                       int minGram,
                                       int maxGram)

Deprecated.

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

Parameters:

version - the Lucene match version

input - TokenStream holding the input to be tokenized

sideLabel - the name of the EdgeNGramTokenFilter.Side from which to chop off an n-gram

minGram - the smallest n-gram to generate

maxGram - the largest n-gram to generate

EdgeNGramTokenFilter

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

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

Parameters:

version - the Lucene match version

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