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

Class ModulusCheckDigit

java.lang.Object
org.apache.commons.validator.routines.checkdigit.ModulusCheckDigit
All Implemented Interfaces:
Serializable, CheckDigit
Direct Known Subclasses:
ABANumberCheckDigit, CASNumberCheckDigit, CUSIPCheckDigit, EAN13CheckDigit, ECNumberCheckDigit, ISBN10CheckDigit, ISINCheckDigit, ISSNCheckDigit, LuhnCheckDigit, ModulusTenCheckDigit, SedolCheckDigit
public abstract class ModulusCheckDigit extends Object implements Serializable
Abstract Modulus Check digit calculation/validation.

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.

Since:
1.4
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    ModulusCheckDigit(int modulus)
    Constructs a CheckDigit routine for a specified modulus.

  • 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.
    int
    getModulus()
    Gets 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.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • ModulusCheckDigit

      public ModulusCheckDigit(int modulus)
      Constructs a CheckDigit routine for a specified modulus.
      Parameters:
      modulus - The modulus value to use for the check digit calculation

  • Method Details

    • sumDigits

      public static int sumDigits(int number)
      Add together the individual digits in a number.
      Parameters:
      number - The number whose digits are to be added
      Returns:
      The sum of the digits

    • calculate

      public String calculate(String code) throws CheckDigitException
      Calculate a modulus Check Digit for a code which does not yet have one.
      Specified by:
      calculate in interface CheckDigit
      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
      Calculate the modulus for a code.
      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

    • getModulus

      public int getModulus()
      Gets the modulus value this check digit routine is based on.
      Returns:
      The modulus value this check digit routine is based on

    • isValid

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

    • toCheckDigit

      protected String toCheckDigit(int charValue) throws CheckDigitException
      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.

      Parameters:
      charValue - 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.

      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 abstract 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.

      Parameters:
      charValue - The numeric value of the character
      leftPos - The position of the character in the code, counting from left to right
      rightPos - The positionof 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