public final class LuhnValidator extends ModulusValidator<Luhn>
Luhn check digits are used, for example, by:
See Wikipedia for more details.
Constructor and Description |
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LuhnValidator() |
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.
|
initialize, isValid, sumDigits, toInt
protected int weightedValue(int charValue, int leftPos, int rightPos) throws Exception
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
Calculates the weighted value of a character in the code at a specified position.Some modulus routines weight the value of a character depending on its position in the code (e.g. ISBN-10), while others use different weighting factors for odd/even positions (e.g. EAN or Luhn). Implement the appropriate mechanism required by overriding this method.
weightedValue
in class ModulusValidator<Luhn>
charValue
- The numeric value of the characterleftPos
- The position of the character in the code, counting from left to rightrightPos
- The position of the character in the code, counting from right to leftException
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