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

Class ISSNCheckDigit

  • All Implemented Interfaces:
    java.io.Serializable, CheckDigit
    public final class ISSNCheckDigit
extends ModulusCheckDigit
    International Standard Serial Number (ISSN) is an eight-digit serial number used to uniquely identify a serial publication. 
     
 The format is:
 
 ISSN dddd-dddC
 where:
 d = decimal digit (0-9)
 C = checksum (0-9 or X)
 
 The checksum is formed by adding the first 7 digits multiplied by
 the position in the entire number (counting from the right).
 For example, abcd-efg would be 8a + 7b + 6c + 5d + 4e +3f +2g.
 The check digit is modulus 11, where the value 10 is represented by 'X'
 For example:
 ISSN 0317-8471
 ISSN 1050-124X

    Note: This class expects the input to be numeric only, with all formatting removed. For example: 

     03178471
 1050124X
    Since:
    1.5.0
    See Also:
    Serialized Form

    • Constructor Summary

      Constructors 
      Constructor Description
      ISSNCheckDigit()  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected java.lang.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 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

    • Field Detail

      • ISSN_CHECK_DIGIT

        public static final CheckDigit ISSN_CHECK_DIGIT
        Singleton ISSN Check Digit instance

    • Constructor Detail

      • ISSNCheckDigit

        public ISSNCheckDigit()

    • Method Detail

      • weightedValue

        protected int weightedValue​(int charValue,
                            int leftPos,
                            int rightPos)
                     throws CheckDigitException
        Description copied from class: ModulusCheckDigit
        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.

        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 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

      • toCheckDigit

        protected java.lang.String toCheckDigit​(int charValue)
                                 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:
        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
        Description copied from class: ModulusCheckDigit
        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:
        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