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

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

  `calculate, calculateModulus, getModulus, isValid, sumDigits, toCheckDigit, toInt`

  ### Methods inherited from class java.lang.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

  - ### 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.