Class ColognePhonetic
- java.lang.Object
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- org.apache.commons.codec.language.ColognePhonetic
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- All Implemented Interfaces:
Encoder
,StringEncoder
public class ColognePhonetic extends java.lang.Object implements StringEncoder
Encodes a string into a Cologne Phonetic value.Implements the Kölner Phonetik (Cologne Phonetic) algorithm issued by Hans Joachim Postel in 1969.
The Kölner Phonetik is a phonetic algorithm which is optimized for the German language. It is related to the well-known soundex algorithm.
Algorithm
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Step 1:
After preprocessing (conversion to upper case, transcription of germanic umlauts, removal of non alphabetical characters) the letters of the supplied text are replaced by their phonetic code according to the following table.(Source: Wikipedia (de): Kölner Phonetik -- Buchstabencodes) Letter Context Code A, E, I, J, O, U, Y 0 H - B 1 P not before H D, T not before C, S, Z 2 F, V, W 3 P before H G, K, Q 4 C at onset before A, H, K, L, O, Q, R, U, X before A, H, K, O, Q, U, X except after S, Z X not after C, K, Q 48 L 5 M, N 6 R 7 S, Z 8 C after S, Z at onset except before A, H, K, L, O, Q, R, U, X not before A, H, K, O, Q, U, X D, T before C, S, Z X after C, K, Q Example:
"M
üller-L
üdenscheidt" => "MULLERLUDENSCHEIDT" => "6005507500206880022"
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Step 2:
Collapse of all multiple consecutive code digits.Example:
"6005507500206880022" => "6050750206802"
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Step 3:
Removal of all codes "0" except at the beginning. This means that two or more identical consecutive digits can occur if they occur after removing the "0" digits.Example:
"6050750206802" => "65752682"
This class is thread-safe.
- Since:
- 1.5
- See Also:
- Wikipedia (de): Kölner Phonetik (in German)
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Nested Class Summary
Nested Classes Modifier and Type Class Description private class
ColognePhonetic.CologneBuffer
This class is not thread-safe; the fieldColognePhonetic.CologneBuffer.length
is mutable.private class
ColognePhonetic.CologneInputBuffer
private class
ColognePhonetic.CologneOutputBuffer
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Field Summary
Fields Modifier and Type Field Description private static char[]
AEIJOUY
private static char[]
AHKLOQRUX
private static char[]
AHKOQUX
private static char
CHAR_IGNORE
private static char[]
CKQ
private static char[]
CSZ
private static char[]
DTX
private static char[]
FPVW
private static char[]
GKQ
private static char[]
SZ
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Constructor Summary
Constructors Constructor Description ColognePhonetic()
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description private static boolean
arrayContains(char[] arr, char key)
java.lang.String
colognePhonetic(java.lang.String text)
Implements the Kölner Phonetik algorithm.java.lang.Object
encode(java.lang.Object object)
Encodes an "Object" and returns the encoded content as an Object.java.lang.String
encode(java.lang.String text)
Encodes a String and returns a String.boolean
isEncodeEqual(java.lang.String text1, java.lang.String text2)
Compares the first encoded string to the second encoded string.private char[]
preprocess(java.lang.String text)
Converts the string to upper case and replaces Germanic umlaut characters The following characters are mapped: capital A, umlaut mark capital U, umlaut mark capital O, umlaut mark small sharp s, German
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Field Detail
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AEIJOUY
private static final char[] AEIJOUY
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CSZ
private static final char[] CSZ
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FPVW
private static final char[] FPVW
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GKQ
private static final char[] GKQ
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CKQ
private static final char[] CKQ
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AHKLOQRUX
private static final char[] AHKLOQRUX
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SZ
private static final char[] SZ
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AHKOQUX
private static final char[] AHKOQUX
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DTX
private static final char[] DTX
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CHAR_IGNORE
private static final char CHAR_IGNORE
- See Also:
- Constant Field Values
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Method Detail
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arrayContains
private static boolean arrayContains(char[] arr, char key)
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colognePhonetic
public java.lang.String colognePhonetic(java.lang.String text)
Implements the Kölner Phonetik algorithm.
In contrast to the initial description of the algorithm, this implementation does the encoding in one pass.
- Parameters:
text
- The source text to encode- Returns:
- the corresponding encoding according to the Kölner Phonetik algorithm
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encode
public java.lang.Object encode(java.lang.Object object) throws EncoderException
Description copied from interface:Encoder
Encodes an "Object" and returns the encoded content as an Object. The Objects here may just bebyte[]
orString
s depending on the implementation used.- Specified by:
encode
in interfaceEncoder
- Parameters:
object
- An object to encode- Returns:
- An "encoded" Object
- Throws:
EncoderException
- An encoder exception is thrown if the encoder experiences a failure condition during the encoding process.
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encode
public java.lang.String encode(java.lang.String text)
Description copied from interface:StringEncoder
Encodes a String and returns a String.- Specified by:
encode
in interfaceStringEncoder
- Parameters:
text
- the String to encode- Returns:
- the encoded String
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isEncodeEqual
public boolean isEncodeEqual(java.lang.String text1, java.lang.String text2)
Compares the first encoded string to the second encoded string.- Parameters:
text1
- source text to encode before testing for equality.text2
- source text to encode before testing for equality.- Returns:
true
if the encoding the first string equals the encoding of the second string,false
otherwise
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preprocess
private char[] preprocess(java.lang.String text)
Converts the string to upper case and replaces Germanic umlaut characters The following characters are mapped:- capital A, umlaut mark
- capital U, umlaut mark
- capital O, umlaut mark
- small sharp s, German
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