Class Metaphone
- All Implemented Interfaces:
Encoder
,StringEncoder
Initial Java implementation by William B. Brogden. December, 1997. Permission given by wbrogden for code to be used anywhere.
Hanging on the Metaphone by Lawrence Philips in Computer Language of Dec. 1990, p 39.
Note, that this does not match the algorithm that ships with PHP, or the algorithm found in the Perl implementations:
- Text:Metaphone-1.96 (broken link 4/30/2013)
- Text:Metaphone-1.96 (link checked 4/30/2013)
They have had undocumented changes from the originally published algorithm. For more information, see CODEC-57.
This class is conditionally thread-safe.
The instance field for maximum code length is mutable setMaxCodeLen(int)
but is not volatile, and accesses are not synchronized.
If an instance of the class is shared between threads, the caller needs to ensure that suitable synchronization
is used to ensure safe publication of the value between threads, and must not invoke setMaxCodeLen(int)
after initial setup.
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Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionEncodes an Object using the metaphone algorithm.Encodes a String using the Metaphone algorithm.int
Returns the maxCodeLen.private boolean
isLastChar
(int wdsz, int n) boolean
isMetaphoneEqual
(String str1, String str2) Tests is the metaphones of two strings are identical.private boolean
isNextChar
(StringBuilder string, int index, char c) private boolean
isPreviousChar
(StringBuilder string, int index, char c) private boolean
isVowel
(StringBuilder string, int index) Find the metaphone value of a String.private boolean
regionMatch
(StringBuilder string, int index, String test) void
setMaxCodeLen
(int maxCodeLen) Sets the maxCodeLen.
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Field Details
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VOWELS
Five values in the English language- See Also:
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FRONTV
Variable used in Metaphone algorithm- See Also:
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VARSON
Variable used in Metaphone algorithm- See Also:
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maxCodeLen
private int maxCodeLenThe max code length for metaphone is 4
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Constructor Details
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Metaphone
public Metaphone()
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Method Details
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metaphone
Find the metaphone value of a String. This is similar to the soundex algorithm, but better at finding similar sounding words. All input is converted to upper case. Limitations: Input format is expected to be a single ASCII word with only characters in the A - Z range, no punctuation or numbers.- Parameters:
txt
- String to find the metaphone code for- Returns:
- A metaphone code corresponding to the String supplied
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isVowel
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isPreviousChar
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isNextChar
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regionMatch
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isLastChar
private boolean isLastChar(int wdsz, int n) -
encode
Encodes an Object using the metaphone 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 interfaceEncoder
- Parameters:
obj
- Object to encode- Returns:
- An object (or type java.lang.String) containing the metaphone code which corresponds to the String supplied.
- Throws:
EncoderException
- if the parameter supplied is not of type java.lang.String
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encode
Encodes a String using the Metaphone algorithm.- Specified by:
encode
in interfaceStringEncoder
- Parameters:
str
- String object to encode- Returns:
- The metaphone code corresponding to the String supplied
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isMetaphoneEqual
Tests is the metaphones of two strings are identical.- Parameters:
str1
- First of two strings to comparestr2
- Second of two strings to compare- Returns:
true
if the metaphones of these strings are identical,false
otherwise.
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getMaxCodeLen
public int getMaxCodeLen()Returns the maxCodeLen.- Returns:
- int
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setMaxCodeLen
public void setMaxCodeLen(int maxCodeLen) Sets the maxCodeLen.- Parameters:
maxCodeLen
- The maxCodeLen to set
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