Soundex (Apache Commons Codec 1.11 API)

java.lang.Object
- org.apache.commons.codec.language.Soundex

All Implemented Interfaces:

Encoder, StringEncoder
```
public class Soundex
extends Object
implements StringEncoder
```
Encodes a string into a Soundex value. Soundex is an encoding used to relate similar names, but can also be used as a general purpose scheme to find word with similar phonemes. This class is thread-safe. Although not strictly immutable, the maxLength field is not actually used.

Version:

$Id: Soundex.java 1811347 2017-10-06 15:21:18Z ggregory $

Field Summary

Fields
Modifier and Type	Field and Description
`static char`	`SILENT_MARKER` The marker character used to indicate a silent (ignored) character.
`static Soundex`	`US_ENGLISH` An instance of Soundex using the US_ENGLISH_MAPPING mapping.
`static Soundex`	`US_ENGLISH_GENEALOGY` An instance of Soundex using the mapping as per the Genealogy site: http://www.genealogy.com/articles/research/00000060.html
`static String`	`US_ENGLISH_MAPPING_STRING` This is a default mapping of the 26 letters used in US English.
`static Soundex`	`US_ENGLISH_SIMPLIFIED` An instance of Soundex using the Simplified Soundex mapping, as described here: http://west-penwith.org.uk/misc/soundex.htm

Constructor Summary

Constructors
Constructor and Description
`Soundex()` Creates an instance using US_ENGLISH_MAPPING
`Soundex(char[] mapping)` Creates a soundex instance using the given mapping.
`Soundex(String mapping)` Creates a refined soundex instance using a custom mapping.
`Soundex(String mapping, boolean specialCaseHW)` Creates a refined soundex instance using a custom mapping.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`int`	`difference(String s1, String s2)` Encodes the Strings and returns the number of characters in the two encoded Strings that are the same.
`Object`	`encode(Object obj)` Encodes an Object using the soundex algorithm.
`String`	`encode(String str)` Encodes a String using the soundex algorithm.
`int`	`getMaxLength()` Deprecated. This feature is not needed since the encoding size must be constant. Will be removed in 2.0.
`void`	`setMaxLength(int maxLength)` Deprecated. This feature is not needed since the encoding size must be constant. Will be removed in 2.0.
`String`	`soundex(String str)` Retrieves the Soundex code for a given String object.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SILENT_MARKER
```
public static final char SILENT_MARKER
```
    The marker character used to indicate a silent (ignored) character. These are ignored except when they appear as the first character.
    Note: the US_ENGLISH_MAPPING_STRING does not use this mechanism because changing it might break existing code. Mappings that don't contain a silent marker code are treated as though H and W are silent.
    To override this, use the Soundex(String, boolean) constructor.
    
    Since:
    
    1.11
    
    See Also:
    
    Constant Field Values
  - US_ENGLISH_MAPPING_STRING
```
public static final String US_ENGLISH_MAPPING_STRING
```
    This is a default mapping of the 26 letters used in US English. A value of 0 for a letter position means do not encode, but treat as a separator when it occurs between consonants with the same code.
    (This constant is provided as both an implementation convenience and to allow Javadoc to pick up the value for the constant values page.)
    Note that letters H and W are treated specially. They are ignored (after the first letter) and don't act as separators between consonants with the same code.
    
    See Also:
    
    US_ENGLISH_MAPPING, Constant Field Values
  - US_ENGLISH
```
public static final Soundex US_ENGLISH
```
    An instance of Soundex using the US_ENGLISH_MAPPING mapping. This treats H and W as silent letters. Apart from when they appear as the first letter, they are ignored. They don't act as separators between duplicate codes.
    
    See Also:
    
    US_ENGLISH_MAPPING, US_ENGLISH_MAPPING_STRING
  - US_ENGLISH_SIMPLIFIED
```
public static final Soundex US_ENGLISH_SIMPLIFIED
```
    An instance of Soundex using the Simplified Soundex mapping, as described here: http://west-penwith.org.uk/misc/soundex.htm
    This treats H and W the same as vowels (AEIOUY). Such letters aren't encoded (after the first), but they do act as separators when dropping duplicate codes. The mapping is otherwise the same as for US_ENGLISH
    
    Since:
    
    1.11
  - US_ENGLISH_GENEALOGY
```
public static final Soundex US_ENGLISH_GENEALOGY
```
    An instance of Soundex using the mapping as per the Genealogy site: http://www.genealogy.com/articles/research/00000060.html
    This treats vowels (AEIOUY), H and W as silent letters. Such letters are ignored (after the first) and do not act as separators when dropping duplicate codes.
    The codes for consonants are otherwise the same as for US_ENGLISH_MAPPING_STRING and US_ENGLISH_SIMPLIFIED
    
    Since:
    
    1.11
- Constructor Detail
  - Soundex
```
public Soundex()
```
    Creates an instance using US_ENGLISH_MAPPING
    
    See Also:
    
    Soundex(char[]), US_ENGLISH_MAPPING
  - Soundex
```
public Soundex(char[] mapping)
```
    Creates a soundex instance using the given mapping. This constructor can be used to provide an internationalized mapping for a non-Western character set. Every letter of the alphabet is "mapped" to a numerical value. This char array holds the values to which each letter is mapped. This implementation contains a default map for US_ENGLISH
    If the mapping contains an instance of SILENT_MARKER then H and W are not given special treatment
    
    Parameters:
    
    mapping - Mapping array to use when finding the corresponding code for a given character
  - Soundex
```
public Soundex(String mapping)
```
    Creates a refined soundex instance using a custom mapping. This constructor can be used to customize the mapping, and/or possibly provide an internationalized mapping for a non-Western character set.
    If the mapping contains an instance of SILENT_MARKER then H and W are not given special treatment
    
    Parameters:
    
    mapping - Mapping string to use when finding the corresponding code for a given character
    
    Since:
    
    1.4
  - Soundex
```
public Soundex(String mapping,
               boolean specialCaseHW)
```
    Creates a refined soundex instance using a custom mapping. This constructor can be used to customize the mapping, and/or possibly provide an internationalized mapping for a non-Western character set.
    
    Parameters:
    
    mapping - Mapping string to use when finding the corresponding code for a given character
    
    specialCaseHW - if true, then
    
    Since:
    
    1.11
- Method Detail
  - difference
```
public int difference(String s1,
                      String s2)
               throws EncoderException
```
    Encodes the Strings and returns the number of characters in the two encoded Strings that are the same. This return value ranges from 0 through 4: 0 indicates little or no similarity, and 4 indicates strong similarity or identical values.
    
    Parameters:
    
    s1 - A String that will be encoded and compared.
    
    s2 - A String that will be encoded and compared.
    
    Returns:
    
    The number of characters in the two encoded Strings that are the same from 0 to 4.
    
    Throws:
    
    EncoderException - if an error occurs encoding one of the strings
    
    Since:
    
    1.3
    
    See Also:
    
    SoundexUtils.difference(StringEncoder,String,String), MS T-SQL DIFFERENCE
  - encode
```
public Object encode(Object obj)
              throws EncoderException
```
    Encodes an Object using the soundex 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 java.lang.String.
    
    Specified by:
    
    encode in interface Encoder
    
    Parameters:
    
    obj - Object to encode
    
    Returns:
    
    An object (or type java.lang.String) containing the soundex code which corresponds to the String supplied.
    
    Throws:
    
    EncoderException - if the parameter supplied is not of type java.lang.String
    
    IllegalArgumentException - if a character is not mapped
  - encode
```
public String encode(String str)
```
    Encodes a String using the soundex algorithm.
    
    Specified by:
    
    encode in interface StringEncoder
    
    Parameters:
    
    str - A String object to encode
    
    Returns:
    
    A Soundex code corresponding to the String supplied
    
    Throws:
    
    IllegalArgumentException - if a character is not mapped
  - getMaxLength
```
@Deprecated
public int getMaxLength()
```
    Deprecated. This feature is not needed since the encoding size must be constant. Will be removed in 2.0.
    
    Returns the maxLength. Standard Soundex
    
    Returns:
    
    int
  - setMaxLength
```
@Deprecated
public void setMaxLength(int maxLength)
```
    Deprecated. This feature is not needed since the encoding size must be constant. Will be removed in 2.0.
    
    Sets the maxLength.
    
    Parameters:
    
    maxLength - The maxLength to set
  - soundex
```
public String soundex(String str)
```
    Retrieves the Soundex code for a given String object.
    
    Parameters:
    
    str - String to encode using the Soundex algorithm
    
    Returns:
    
    A soundex code for the String supplied
    
    Throws:
    
    IllegalArgumentException - if a character is not mapped

Class Soundex

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SILENT_MARKER

US_ENGLISH_MAPPING_STRING

US_ENGLISH

US_ENGLISH_SIMPLIFIED

US_ENGLISH_GENEALOGY

Constructor Detail

Soundex

Soundex

Soundex

Soundex

Method Detail

difference

encode

encode

getMaxLength

setMaxLength

soundex