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

Class VerhoeffCheckDigit

  • All Implemented Interfaces:
    java.io.Serializable, CheckDigit
    public final class VerhoeffCheckDigit
extends java.lang.Object
implements CheckDigit, java.io.Serializable
    Verhoeff (Dihedral) Check Digit calculation/validation.

    Check digit calculation for numeric codes using a Dihedral Group of order 10.

    See Wikipedia - Verhoeff algorithm for more details.

    Since:
    Validator 1.4
    Version:
    $Revision: 1649191 $
    See Also:
    Serialized Form

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String calculate​(java.lang.String code)
      Calculate a Verhoeff Check Digit for a code.
      private int calculateChecksum​(java.lang.String code, boolean includesCheckDigit)
      Calculate the checksum.
      boolean isValid​(java.lang.String code)
      Validate the Verhoeff Check Digit for a code.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • VERHOEFF_CHECK_DIGIT

        public static final CheckDigit VERHOEFF_CHECK_DIGIT
        Singleton Verhoeff Check Digit instance

      • D_TABLE

        private static final int[][] D_TABLE
        D - multiplication table

      • P_TABLE

        private static final int[][] P_TABLE
        P - permutation table

      • INV_TABLE

        private static final int[] INV_TABLE
        inv: inverse table

    • Constructor Detail

      • VerhoeffCheckDigit

        public VerhoeffCheckDigit()

    • Method Detail

      • isValid

        public boolean isValid​(java.lang.String code)
        Validate the Verhoeff 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

      • calculate

        public java.lang.String calculate​(java.lang.String code)
                           throws CheckDigitException
        Calculate a Verhoeff Check Digit for a code.
        Specified by:
        calculate in interface CheckDigit
        Parameters:
        code - The code to calculate the Check Digit for
        Returns:
        The calculated Check Digit
        Throws:
        CheckDigitException - if an error occurs calculating the check digit for the specified code

      • calculateChecksum

        private int calculateChecksum​(java.lang.String code,
                              boolean includesCheckDigit)
                       throws CheckDigitException
        Calculate the checksum.
        Parameters:
        code - The code to calculate the checksum for.
        includesCheckDigit - Whether the code includes the Check Digit or not.
        Returns:
        The checksum value
        Throws:
        CheckDigitException - if the code contains an invalid character (i.e. not numeric)