org.apache.bval.extras.constraints.checkdigit

Class EAN13Validator

java.lang.Object

org.apache.bval.extras.constraints.checkdigit.EAN13Validator

All Implemented Interfaces:

javax.validation.ConstraintValidator<EAN13,CharSequence>

public final class EAN13Validator
extends Object

Modulus 10 EAN-13 / UPC / ISBN-13 Check Digit calculation/validation.

Check digit calculation is based on modulus 10 with digits in an odd position (from right to left) being weighted 1 and even position digits being weighted 3.

For further information see:

• EAN-13 - see Wikipedia - European Article Number.
• UPC - see Wikipedia - Universal Product Code.
• ISBN-13 - see Wikipedia - International Standard Book Number (ISBN).

Constructor Summary

Constructors

Constructor and Description
EAN13Validator()

Method Summary

Modifier and Type	Method and Description
void	initialize(A annotation)
boolean	isValid(CharSequence code, javax.validation.ConstraintValidatorContext context)
protected static int	sumDigits(int number) Add together the individual digits in a number.
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

Constructor Detail

EAN13Validator

public EAN13Validator()

Method Detail

weightedValue

protected int weightedValue(int charValue,
                            int leftPos,
                            int rightPos)
                     throws Exception

Calculates the weighted value of a character in the code at a specified position.

For EAN-13 (from right to left) odd digits are weighted with a factor of one and even digits with a factor of three.

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 position of the character in the code, counting from right to left

Returns:

The weighted value of the character

Throws:

Exception

initialize

public final void initialize(A annotation)

Specified by:

initialize in interface javax.validation.ConstraintValidator<A extends Annotation,CharSequence>

isValid

public boolean isValid(CharSequence code,
                       javax.validation.ConstraintValidatorContext context)

Specified by:

isValid in interface javax.validation.ConstraintValidator<A extends Annotation,CharSequence>

toInt

protected int toInt(char character,
                    int leftPos,
                    int rightPos)

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

rightPos - The positionof the character in the code, counting from right to left

Returns:

The integer value of the character

sumDigits

protected 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