Package org.apache.commons.validator.routines.checkdigit

Class IsoIec7064PureSystem

java.lang.Object
org.apache.commons.validator.routines.checkdigit.ModulusCheckDigit
org.apache.commons.validator.routines.checkdigit.IsoIec7064PureSystem
All Implemented Interfaces:
Serializable, CheckDigit
Direct Known Subclasses:
IsoIec7064PurePolynomialSystem, IsoIecPure11System, IsoIecPure1271System, IsoIecPure37System, IsoIecPure661System, IsoIecPure97System, Modulus97CheckDigit
public abstract class IsoIec7064PureSystem extends ModulusCheckDigit
Abstract implementation for five check digit calculation/validation defined in the ISO/IEC 7064 standard.

Pure system algorithms use a single modulus value ModulusCheckDigit.getModulus() and a radix getRadix(), f.i. the modulus for MOD 11-2 is 11, the radix is 2. There is also an alternative polynomial implementation for the pure systems, see IsoIec7064PurePolynomialSystem and subclasses.

The standard also defines hybrid systems with two modulus values (see IsoIec7064HybridSystem).

Since:
1.10.0
Author:
EUG https://github.com/homebeaver
See Also:

  • Method Summary

    Modifier and Type
    Method
    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.
    protected abstract String
    getCharacterSet()
    MOD 11-2 check characters are “0” to “9” plus “X” for example.
    int
    getCheckdigitLength()
    Returns the lentgth of the check digit for the system
    protected abstract int
    getRadix()
    Radix is the second number following “MOD” in the ISO/IEC designation, f.i. 2 for "MOD 11-2"
    boolean
    isValid(String code)
    Validate a modulus check digit for a code.
    protected String
    toCheckDigit(int checksum)
    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 int
    weightedValue(int charValue, int leftPos, int rightPos)
    Calculates the weighted value of a character in the code at a specified position.

    Methods inherited from class org.apache.commons.validator.routines.checkdigit.ModulusCheckDigit

    getModulus, sumDigits

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • getRadix

      protected abstract int getRadix()
      Radix is the second number following “MOD” in the ISO/IEC designation, f.i. 2 for "MOD 11-2"
      Returns:
      the radix of the Check Digit routine

    • getCharacterSet

      protected abstract String getCharacterSet()
      MOD 11-2 check characters are “0” to “9” plus “X” for example.
      Returns:
      a String containing characters the check digit is build from. This can be IsoIecConstants.NUMERIC, IsoIecConstants.ALPHABETIC, IsoIecConstants.ALPHANUMERIC , IsoIecConstants.NUMERIC_PLUS_X, IsoIecConstants.ALPHANUMERIC_PLUS_STAR

    • getCheckdigitLength

      public int getCheckdigitLength()
      Returns the lentgth of the check digit for the system
      Returns:
      checkdigitLength can be one ore two chars

    • isValid

      public boolean isValid(String code)
      Description copied from class: ModulusCheckDigit
      Validate a modulus check digit for a code.
      Specified by:
      isValid in interface CheckDigit
      Overrides:
      isValid in class ModulusCheckDigit
      Parameters:
      code - The code to validate
      Returns:
      true if the check digit is valid, otherwise false

    • calculate

      public String calculate(String code) throws CheckDigitException
      Description copied from class: ModulusCheckDigit
      Calculate a modulus Check Digit for a code which does not yet have one.
      Specified by:
      calculate in interface CheckDigit
      Overrides:
      calculate in class ModulusCheckDigit
      Parameters:
      code - The code for which to calculate the Check Digit; the check digit should not be included
      Returns:
      The calculated Check Digit
      Throws:
      CheckDigitException - if an error occurs calculating the check digit

    • calculateModulus

      protected int calculateModulus(String code, boolean includesCheckDigit) throws CheckDigitException
      Description copied from class: ModulusCheckDigit
      Calculate the modulus for a code.
      Overrides:
      calculateModulus in class ModulusCheckDigit
      Parameters:
      code - The code to calculate the modulus for.
      includesCheckDigit - Whether the code includes the Check Digit or not.
      Returns:
      The modulus value
      Throws:
      CheckDigitException - if an error occurs calculating the modulus for the specified code

    • toCheckDigit

      protected String toCheckDigit(int checksum) throws CheckDigitException
      Description copied from class: ModulusCheckDigit
      Convert an integer value to a check digit.

      Note: this implementation only handles single-digit numeric values For non-numeric characters, override this method to provide integer-->character conversion.

      Overrides:
      toCheckDigit in class ModulusCheckDigit
      Parameters:
      checksum - The integer value of the character
      Returns:
      The converted character
      Throws:
      CheckDigitException - if integer character value doesn't represent a numeric character

    • toInt

      protected int toInt(char character, int leftPos, int rightPos) throws CheckDigitException
      Convert a character at a specified position to an integer value.

      Note: this implementation only handlers numeric values For non-numeric characters, override this method to provide character-->integer conversion.

      Overrides to handle numeric, alphabetic or alphanumeric values respectively.

      Overrides:
      toInt in class ModulusCheckDigit
      Parameters:
      character - The character to convert
      leftPos - 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)
      Returns:
      The integer value of the character
      Throws:
      CheckDigitException - if character is non-numeric

    • weightedValue

      protected int weightedValue(int charValue, int leftPos, int rightPos) throws CheckDigitException
      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.

      Overrides because there is no need for a weight in ISO/IEC 7064 pure recursive/iterative computation. However for polynomial calculation this method is used.

      Weights are defined in subclasses for the first fifteen positions only. The series can be extended indefinitely, using the formula 

       wi = r^(i - 1) (mod M)
      where wi is the weight for Position i.

      NOTE: do not use Math.pow for high results, f.i. 10^23 (mod 97) = 56. Calculate it iteratively instead.

      Specified by:
      weightedValue in class ModulusCheckDigit
      Parameters:
      charValue - The numeric value of the character
      leftPos - The position of the character in the code, counting from left to right
      rightPos - The position of the character in the code, counting from right to left
      Returns:
      The weighted value of the character
      Throws:
      CheckDigitException - if an error occurs calculating the weighted value