public final class LuhnCheckDigit extends ModulusCheckDigit
See Wikipedia for more details.
Modifier and Type | Field and Description |
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static CheckDigit |
LUHN_CHECK_DIGIT
Singleton Luhn Check Digit instance
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Constructor and Description |
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LuhnCheckDigit()
Construct a modulus 10 Luhn Check Digit routine.
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Modifier and Type | Method and Description |
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protected int |
weightedValue(int charValue,
int leftPos,
int rightPos)
Calculates the weighted value of a charcter in the
code at a specified position.
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calculate, calculateModulus, getModulus, isValid, sumDigits, toCheckDigit, toInt
public static final CheckDigit LUHN_CHECK_DIGIT
public LuhnCheckDigit()
protected int weightedValue(int charValue, int leftPos, int rightPos)
Calculates the weighted value of a charcter in the code at a specified position.
For Luhn (from right to left) odd digits are weighted with a factor of one and even digits with a factor of two. Weighted values > 9, have 9 subtracted
weightedValue
in class ModulusCheckDigit
charValue
- The numeric value of the character.leftPos
- The position of the character in the code, counting from left to rightrightPos
- The positionof the character in the code, counting from right to leftCopyright © 2002–2017 The Apache Software Foundation. All rights reserved.