Class ABANumberCheckDigit

java.lang.Object

org.apache.commons.validator.routines.checkdigit.ModulusCheckDigit

org.apache.commons.validator.routines.checkdigit.ABANumberCheckDigit

All Implemented Interfaces:

Serializable, CheckDigit

public final class ABANumberCheckDigit
extends ModulusCheckDigit

Modulus 10 ABA Number (or Routing Transit Number (RTN)) Check Digit calculation/validation.

ABA Numbers (or Routing Transit Numbers) are a nine digit numeric code used to identify American financial institutions for things such as checks or deposits (ABA stands for the American Bankers Association).

Check digit calculation is based on modulus 10 with digits being weighted based on their position (from right to left) as follows:

• Digits 1, 4 and & 7 are weighted 1
• Digits 2, 5 and & 8 are weighted 7
• Digits 3, 6 and & 9 are weighted 3

For further information see Wikipedia - Routing transit number.

Since:

1.4

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final CheckDigit	ABAN_CHECK_DIGIT	Singleton Routing Transit Number Check Digit instance.

Constructor Summary

Constructors

Constructor	Description
ABANumberCheckDigit()	Constructs a modulus 10 Check Digit routine for ABA Numbers.

Method Summary

Modifier and Type	Method	Description
boolean	isValid(String code)	Validates a modulus check digit for a code.
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 ModulusCheckDigit

calculate, calculateModulus, getModulus, sumDigits, toCheckDigit, toInt

Modifier and Type	Method	Description
String	calculate(String code)	Calculates a modulus Check Digit for a code which does not yet have one.
protected int	calculateModulus(String code, boolean includesCheckDigit)	Calculates the modulus for a code.
int	getModulus()	Gets the modulus value this check digit routine is based on.
static int	sumDigits(int number)	Adds together the individual digits in a number.
protected String	toCheckDigit(int charValue)	Converts an integer value to a check digit.
protected int	toInt(char character, int leftPos, int rightPos)	Converts a character at a specified position to an integer value.

Methods inherited from class Object

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

Field Details

ABAN_CHECK_DIGIT

public static final CheckDigit ABAN_CHECK_DIGIT

Singleton Routing Transit Number Check Digit instance.

Constructor Details

ABANumberCheckDigit

public ABANumberCheckDigit()

Constructs a modulus 10 Check Digit routine for ABA Numbers.

Method Details

isValid

public boolean isValid(String code)

Validates a modulus check digit for a code.

The weight is taken from rightPos, which does not change when a character is prepended, so ModulusCheckDigit would accept an over-length code whose leading digit lands on a no-op weight (for example 0123456780). The nine-character length is checked here before the check digit test.

Specified by:

isValid in interface CheckDigit

Overrides:

isValid in class ModulusCheckDigit

Parameters:

code - The code to validate.

Returns:

true if the check digit is valid, otherwise false.

weightedValue

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

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

ABA Routing numbers are weighted in the following manner:

    left position: 1  2  3  4  5  6  7  8  9
           weight: 3  7  1  3  7  1  3  7  1

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.