public abstract class ModulusCheckDigit extends Object implements CheckDigit, Serializable
Provides a base class for building modulus Check Digit routines.
This implementation only handles single-digit numeric codes, such as
EAN-13. For alphanumeric codes such as EAN-128 you
will need to implement/override the toInt() and
toChar() methods.
| Constructor and Description |
|---|
ModulusCheckDigit(int modulus)
Construct a
CheckDigit routine for a specified modulus. |
| Modifier and Type | Method and Description |
|---|---|
String |
calculate(String code)
Calculate a modulus Check Digit for a code which does not yet have one.
|
protected int |
calculateModulus(String code,
boolean includesCheckDigit)
Calculate the modulus for a code.
|
int |
getModulus()
Return the modulus value this check digit routine is based on.
|
boolean |
isValid(String code)
Validate a modulus check digit for a code.
|
static int |
sumDigits(int number)
Add together the individual digits in a number.
|
protected String |
toCheckDigit(int charValue)
Convert an integer value to a check digit.
|
protected int |
toInt(char character,
int leftPos,
int rightPos)
Convert a character at a specified position to an integer value.
|
protected abstract int |
weightedValue(int charValue,
int leftPos,
int rightPos)
Calculates the weighted value of a character in the
code at a specified position.
|
public ModulusCheckDigit(int modulus)
CheckDigit routine for a specified modulus.modulus - The modulus value to use for the check digit calculationpublic int getModulus()
public boolean isValid(String code)
isValid in interface CheckDigitcode - The code to validatetrue if the check digit is valid, otherwise
falsepublic String calculate(String code) throws CheckDigitException
calculate in interface CheckDigitcode - The code for which to calculate the Check Digit;
the check digit should not be includedCheckDigitException - if an error occurs calculating the check digitprotected int calculateModulus(String code, boolean includesCheckDigit) throws CheckDigitException
code - The code to calculate the modulus for.includesCheckDigit - Whether the code includes the Check Digit or not.CheckDigitException - if an error occurs calculating the modulus
for the specified codeprotected abstract int weightedValue(int charValue,
int leftPos,
int rightPos)
throws CheckDigitException
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.
charValue - The numeric value of the characterleftPos - The position of the character in the code, counting from left to rightrightPos - The positionof the character in the code, counting from right to leftCheckDigitException - if an error occurs calculating
the weighted valueprotected int toInt(char character,
int leftPos,
int rightPos)
throws CheckDigitException
Note: this implementation only handlers numeric values For non-numeric characters, override this method to provide character-->integer conversion.
character - The character to convertleftPos - The position of the character in the code, counting from left to right (for identifiying the position in the string)rightPos - The position of the character in the code, counting from right to left (not used here)CheckDigitException - if character is non-numericprotected String toCheckDigit(int charValue) throws CheckDigitException
Note: this implementation only handles single-digit numeric values For non-numeric characters, override this method to provide integer-->character conversion.
charValue - The integer value of the characterCheckDigitException - if integer character value
doesn't represent a numeric characterpublic static int sumDigits(int number)
number - The number whose digits are to be addedCopyright © 2002–2020 The Apache Software Foundation. All rights reserved.