org.apache.lucene.search
Class FuzzyTermEnum

java.lang.Object
  extended by org.apache.lucene.index.TermEnum
      extended by org.apache.lucene.search.FilteredTermEnum
          extended by org.apache.lucene.search.FuzzyTermEnum
All Implemented Interfaces:
Closeable

public final class FuzzyTermEnum
extends FilteredTermEnum

Subclass of FilteredTermEnum for enumerating all terms that are similar 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.


Field Summary
 
Fields inherited from class org.apache.lucene.search.FilteredTermEnum
actualEnum, currentTerm
 
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()
          Indicates 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
docFreq, next, setEnum, term
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

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 -
Throws:
IOException
See Also:
FuzzyTermEnum(IndexReader, Term, float, int)

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 -
Throws:
IOException
See Also:
FuzzyTermEnum(IndexReader, Term, float, int)

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.
Throws:
IOException
Method Detail

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.

Specified by:
termCompare in class FilteredTermEnum

difference

public final float difference()
Equality measure on the term

Specified by:
difference in class FilteredTermEnum

endEnum

public final boolean endEnum()
Indicates the end of the enumeration has been reached

Specified by:
endEnum in class FilteredTermEnum

close

public void close()
           throws IOException
Closes the enumeration to further activity, freeing resources.

Specified by:
close in interface Closeable
Overrides:
close in class FilteredTermEnum
Throws:
IOException


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