Class BCDUtil

java.lang.Object
javacardx.framework.math.BCDUtil
public final class BCDUtil extends Object
The BCDUtil class contains common BCD(binary coded decimal) related utility functions. This class supports Packed BCD format. All methods in this class are static.

The BCDUtil class only supports unsigned numbers whose value can are represented in hexadecimal format using an implementation specific maximum number of bytes.

Since:
2.2.2

  • Constructor Summary

    Constructors
    Constructor
    Description
    BCDUtil()
    Intended to be package visible.

  • Method Summary

    Modifier and Type
    Method
    Description
    static short
    convertToBCD(byte[] hexArray, short bOff, short bLen, byte[] bcdArray, short outOff)
    Converts the input hexadecimal data into BCD format.
    static short
    convertToHex(byte[] bcdArray, short bOff, short bLen, byte[] hexArray, short outOff)
    Converts the input BCD data into hexadecimal format.
    static short
    getMaxBytesSupported()
    This method returns the largest value that can be used with the BCD utility functions.
    static boolean
    isBCDFormat(byte[] bcdArray, short bOff, short bLen)
    Checks if the input data is in BCD format.

    Methods inherited from class Object

    equals
    Modifier and Type
    Method
    Description
    boolean
    equals(Object obj)
    Compares two Objects for equality.

  • Constructor Details

    • BCDUtil

      public BCDUtil()
      Intended to be package visible. Retain for compatibility

  • Method Details

    • getMaxBytesSupported

      public static short getMaxBytesSupported()
      This method returns the largest value that can be used with the BCD utility functions. This number represents the byte length of the largest value in hex byte representation. All implementations must support at least 8 byte length usage capacity.
      Returns:
      the byte length of the largest hex value supported

    • convertToHex

      public static short convertToHex(byte[] bcdArray, short bOff, short bLen, byte[] hexArray, short outOff)
      Converts the input BCD data into hexadecimal format.

      Note:

      • If bOff or bLen or outOff parameter is negative an ArrayIndexOutOfBoundsException exception is thrown.
      • If bOff+bLen is greater than bcdArray.length, the length of the bcdArray array a ArrayIndexOutOfBoundsException exception is thrown and no conversion is performed.
      • If the output bytes need to be written at an offset greater than hexArray.length, the length of the hexArray array an ArrayIndexOutOfBoundsException exception is thrown and no conversion is performed.
      • If bcdArray or hexArray parameter is null a NullPointerException exception is thrown.
      • If the bcdArray and hexArray arguments refer to the same array object, or if any of these arguments refer to an array view sharing components with the other argument, then the conversion is performed as if the components at positions bOff through bOff+bLen-1 were first copied to a temporary array with bLen components and then the contents of the temporary array were converted into positions outOff onwards for the converted bytes of the output array.

      Parameters:
      bcdArray - input byte array
      bOff - offset within byte array containing first byte (the high order byte)
      bLen - byte length of input BCD data
      hexArray - output byte array
      outOff - offset within hexArray where output data begins
      Returns:
      the byte length of the output hexadecimal data
      Throws:
      ArrayIndexOutOfBoundsException - if converting would cause access of data outside array bounds or if bLen is negative
      NullPointerException - if either bcdArray or hexArray is null
      ArithmeticException - for the following conditions:
      • if the input byte array format is not a correctly formed BCD value
      • the size of the BCD value requires greater than supported maximum number of bytes to represent in hex format
      • if bLen is 0

    • convertToBCD

      public static short convertToBCD(byte[] hexArray, short bOff, short bLen, byte[] bcdArray, short outOff)
      Converts the input hexadecimal data into BCD format. The output data is right justified. If the number of output BCD nibbles is odd, the first BCD nibble written is 0.

      Note:

      • If bOff or bLen or outOff parameter is negative an ArrayIndexOutOfBoundsException exception is thrown.
      • If bOff+bLen is greater than hexArray.length, the length of the hexArray array a ArrayIndexOutOfBoundsException exception is thrown and no conversion is performed.
      • If the output bytes need to be written at an offset greater than bcdArray.length, the length of the bcdArray array an ArrayIndexOutOfBoundsException exception is thrown and no conversion is performed.
      • If bcdArray or hexArray parameter is null a NullPointerException exception is thrown.
      • If the bcdArray and hexArray arguments refer to the same array object, or if any of these arguments refer to an array view sharing components with the other argument, then the conversion is performed as if the components at positions bOff through bOff+bLen-1 were first copied to a temporary array with bLen components and then the contents of the temporary array were converted into positions outOff onwards for the converted bytes of the output array.

      Parameters:
      hexArray - input byte array
      bOff - offset within byte array containing first byte (the high order byte)
      bLen - byte length of input hex data
      bcdArray - output byte array
      outOff - offset within bcdArray where output data begins
      Returns:
      the byte length of the output bcd formatted data
      Throws:
      ArrayIndexOutOfBoundsException - if converting would cause access of data outside array bounds or if bLen is negative
      NullPointerException - if either bcdArray or hexArray is null
      ArithmeticException - for the following conditions:
      • if the length of the input hex value is larger than the supported maximum number of bytes
      • if bLen is 0

    • isBCDFormat

      public static boolean isBCDFormat(byte[] bcdArray, short bOff, short bLen)
      Checks if the input data is in BCD format. Note that this method does not enforce an upper bound on the length of the input BCD value.
      Parameters:
      bcdArray - input byte array
      bOff - offset within byte array containing first byte (the high order byte)
      bLen - byte length of input BCD data
      Returns:
      true if input data is in BCD format, false otherwise
      Throws:
      ArrayIndexOutOfBoundsException - if accessing the input array would cause access of data outside array bounds or if bLen is negative
      NullPointerException - if bcdArray is null
      ArithmeticException - if bLen is 0