org.apache.lucene.search

Class FuzzyTermEnum


public final class FuzzyTermEnum
extends FilteredTermEnum

Subclass of FilteredTermEnum for enumerating all terms that are similiar to the specified filter term.

Term enumerations are always ordered by Term.compareTo(). Each term in the enumeration is greater than all that precede it.

Constructor Summary

FuzzyTermEnum(IndexReader reader, Term term)
Creates a FuzzyTermEnum with an empty prefix and a minSimilarity of 0.5f.
FuzzyTermEnum(IndexReader reader, Term term, float minSimilarity)
Creates a FuzzyTermEnum with an empty prefix.
FuzzyTermEnum(IndexReader reader, Term term, float minSimilarity, int prefixLength)
Constructor for enumeration of all terms from specified reader which share a prefix of length prefixLength with term and which have a fuzzy similarity > minSimilarity.

Method Summary

void
close()
Closes the enumeration to further activity, freeing resources.
float
difference()
Equality measure on the term
boolean
endEnum()
Indiciates the end of the enumeration has been reached
protected boolean
termCompare(Term term)
The termCompare method in FuzzyTermEnum uses Levenshtein distance to calculate the distance between the given term and the comparing term.

Methods inherited from class org.apache.lucene.search.FilteredTermEnum

close, difference, docFreq, endEnum, next, setEnum, term, termCompare

Methods inherited from class org.apache.lucene.index.TermEnum

close, docFreq, next, skipTo, term

Constructor Details

FuzzyTermEnum

public FuzzyTermEnum(IndexReader reader,
                     Term term)
            throws IOException
Creates a FuzzyTermEnum with an empty prefix and a minSimilarity of 0.5f.

After calling the constructor the enumeration is already pointing to the first valid term if such a term exists.

Parameters:
reader -
term -

FuzzyTermEnum

public FuzzyTermEnum(IndexReader reader,
                     Term term,
                     float minSimilarity)
            throws IOException
Creates a FuzzyTermEnum with an empty prefix.

After calling the constructor the enumeration is already pointing to the first valid term if such a term exists.

Parameters:
reader -
term -
minSimilarity -

FuzzyTermEnum

public FuzzyTermEnum(IndexReader reader,
                     Term term,
                     float minSimilarity,
                     int prefixLength)
            throws IOException
Constructor for enumeration of all terms from specified reader which share a prefix of length prefixLength with term and which have a fuzzy similarity > minSimilarity.

After calling the constructor the enumeration is already pointing to the first valid term if such a term exists.

Parameters:
reader - Delivers terms.
term - Pattern term.
minSimilarity - Minimum required similarity for terms from the reader. Default value is 0.5f.
prefixLength - Length of required common prefix. Default value is 0.

Method Details

close

public void close()
            throws IOException
Closes the enumeration to further activity, freeing resources.
Overrides:
close in interface FilteredTermEnum

difference

public final float difference()
Equality measure on the term
Overrides:
difference in interface FilteredTermEnum

endEnum

public final boolean endEnum()
Indiciates the end of the enumeration has been reached
Overrides:
endEnum in interface FilteredTermEnum

termCompare

protected final boolean termCompare(Term term)
The termCompare method in FuzzyTermEnum uses Levenshtein distance to calculate the distance between the given term and the comparing term.
Overrides:
termCompare in interface FilteredTermEnum

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