Package org.apache.commons.codec.language

Class Nysiis

  • All Implemented Interfaces:
    Encoder, StringEncoder
    public class Nysiis
extends java.lang.Object
implements StringEncoder
    Encodes a string into a NYSIIS value. NYSIIS is an encoding used to relate similar names, but can also be used as a general purpose scheme to find word with similar phonemes.

    NYSIIS features an accuracy increase of 2.7% over the traditional Soundex algorithm.

    Algorithm description: 

     1. Transcode first characters of name
   1a. MAC ->   MCC
   1b. KN  ->   NN
   1c. K   ->   C
   1d. PH  ->   FF
   1e. PF  ->   FF
   1f. SCH ->   SSS
 2. Transcode last characters of name
   2a. EE, IE          ->   Y
   2b. DT,RT,RD,NT,ND  ->   D
 3. First character of key = first character of name
 4. Transcode remaining characters by following these rules, incrementing by one character each time
   4a. EV  ->   AF  else A,E,I,O,U -> A
   4b. Q   ->   G
   4c. Z   ->   S
   4d. M   ->   N
   4e. KN  ->   N   else K -> C
   4f. SCH ->   SSS
   4g. PH  ->   FF
   4h. H   ->   If previous or next is nonvowel, previous
   4i. W   ->   If previous is vowel, previous
   4j. Add current to key if current != last key character
 5. If last character is S, remove it
 6. If last characters are AY, replace with Y
 7. If last character is A, remove it
 8. Collapse all strings of repeated characters
 9. Add original first character of name as first character of key

    This class is immutable and thread-safe.

    Since:
    1.7
    See Also:
    NYSIIS on Wikipedia, NYSIIS on dropby.com, Soundex

    • Constructor Summary

      Constructors 
      Constructor Description
      Nysiis()
      Creates an instance of the Nysiis encoder with strict mode (original form), i.e.
      Nysiis​(boolean strict)
      Create an instance of the Nysiis encoder with the specified strict mode: true: encoded strings have a maximum length of 6 false: encoded strings may have arbitrary length

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.Object encode​(java.lang.Object obj)
      Encodes an Object using the NYSIIS algorithm.
      java.lang.String encode​(java.lang.String str)
      Encodes a String using the NYSIIS algorithm.
      boolean isStrict()
      Indicates the strict mode for this Nysiis encoder.
      java.lang.String nysiis​(java.lang.String str)
      Retrieves the NYSIIS code for a given String object.

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • Nysiis

        public Nysiis()
        Creates an instance of the Nysiis encoder with strict mode (original form), i.e. encoded strings have a maximum length of 6.

      • Nysiis

        public Nysiis​(boolean strict)
        Create an instance of the Nysiis encoder with the specified strict mode:
        • true: encoded strings have a maximum length of 6
        • false: encoded strings may have arbitrary length
        Parameters:
        strict - the strict mode

    • Method Detail

      • encode

        public java.lang.Object encode​(java.lang.Object obj)
                        throws EncoderException
        Encodes an Object using the NYSIIS algorithm. This method is provided in order to satisfy the requirements of the Encoder interface, and will throw an EncoderException if the supplied object is not of type String.
        Specified by:
        encode in interface Encoder
        Parameters:
        obj - Object to encode
        Returns:
        An object (or a String) containing the NYSIIS code which corresponds to the given String.
        Throws:
        EncoderException - if the parameter supplied is not of a String
        java.lang.IllegalArgumentException - if a character is not mapped

      • encode

        public java.lang.String encode​(java.lang.String str)
        Encodes a String using the NYSIIS algorithm.
        Specified by:
        encode in interface StringEncoder
        Parameters:
        str - A String object to encode
        Returns:
        A Nysiis code corresponding to the String supplied
        Throws:
        java.lang.IllegalArgumentException - if a character is not mapped

      • isStrict

        public boolean isStrict()
        Indicates the strict mode for this Nysiis encoder.
        Returns:
        true if the encoder is configured for strict mode, false otherwise

      • nysiis

        public java.lang.String nysiis​(java.lang.String str)
        Retrieves the NYSIIS code for a given String object.
        Parameters:
        str - String to encode using the NYSIIS algorithm
        Returns:
        A NYSIIS code for the String supplied