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

Class ISSNCheckDigit

java.lang.Object
org.apache.commons.validator.routines.checkdigit.ModulusCheckDigit
org.apache.commons.validator.routines.checkdigit.ISSNCheckDigit
All Implemented Interfaces:
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:

  • Field Details

  • Constructor Details

    • ISSNCheckDigit

      public ISSNCheckDigit()
      Creates the instance using a checkdigit modulus of 11.

  • Method Details

    • toCheckDigit

      protected 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

    • 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 (for example, ISBN-10), while others use different weighting factors for odd/even positions (for example, 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 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