edu.iastate.metnet.utils
Class HexUtil

java.lang.Object
  edu.iastate.metnet.utils.HexUtil

public class HexUtil
extends java.lang.Object

Copyright c2001-2004 Trygve Isaacson. All Rights Reserved. Contains utility functions for converting between hexadecimal strings and their equivalent byte buffers or String objects.

Constructor Summary

HexUtil()

Method Summary

static java.lang.String	bufferToHex(byte[] buffer) Returns a string containing the hexadecimal representation of the input byte array.
static java.lang.String	bufferToHex(byte[] buffer, int startOffset, int length) Returns a string containing the hexadecimal representation of the input byte array.
static byte[]	hexToBuffer(java.lang.String hexString) Returns a byte array built from the byte values represented by the input hexadecimal string.
static java.lang.String	hexToString(java.lang.String hexString) Returns a string built from the byte values represented by the input hexadecimal string.
static java.lang.String	stringToHex(java.lang.String s) Returns a string containing the hexadecimal representation of the input string.

Methods inherited from class java.lang.Object

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

Constructor Detail

HexUtil

public HexUtil()

Method Detail

stringToHex

public static java.lang.String stringToHex(java.lang.String s)

Returns a string containing the hexadecimal representation of the input string. Each byte in the input string is converted to a two-digit hexadecimal value. Thus the returned string is twice the length of the input string. The output hex characters are upper case. The conversion assumes the default charset; making the charset explicit could be accomplished by just adding a parameter here and passing it through to getBytes().

Parameters:

s - a string to convert to hex

Returns:

the hex string version of the input string

bufferToHex

public static java.lang.String bufferToHex(byte[] buffer)

Returns a string containing the hexadecimal representation of the input byte array. Each byte in the input array is converted to a two-digit hexadecimal value. Thus the returned string is twice the length of the input byte array. The output hex characters are upper case.

Parameters:

buffer - a buffer to convert to hex

Returns:

the hex string version of the input buffer

bufferToHex

public static java.lang.String bufferToHex(byte[] buffer,
                                           int startOffset,
                                           int length)

Returns a string containing the hexadecimal representation of the input byte array. Each byte in the input array is converted to a two-digit hexadecimal value. Thus the returned string is twice the length of the specified amount of the input byte array. The output hex characters are upper case.

Parameters:

buffer - a buffer to convert to hex

startOffset - the offset of the first byte in the buffer to process

length - the number of bytes in the buffer to process

Returns:

the hex string version of the input buffer

hexToString

public static java.lang.String hexToString(java.lang.String hexString)
                                    throws java.lang.NumberFormatException

Returns a string built from the byte values represented by the input hexadecimal string. That is, each pair of hexadecimal characters in the input string is decoded into the byte value that they represent, and that byte value is appended to a string which is ultimately returned. This function doesn't care whether the hexadecimal characters are upper or lower case, and it also can handle odd-length hex strings by assuming a leading zero digit. If any character in the input string is not a valid hexadecimal digit, it throws a NumberFormatException, in keeping with the behavior of Java functions like Integer.parseInt(). The conversion assumes the default charset; making the charset explicit could be accomplished by just adding a parameter here and passing it through to the String constructor.

Parameters:

hexString - a string of hexadecimal characters

Returns:

a String built from the bytes indicated by the input string

Throws:

java.lang.NumberFormatException

hexToBuffer

public static byte[] hexToBuffer(java.lang.String hexString)
                          throws java.lang.NumberFormatException

Returns a byte array built from the byte values represented by the input hexadecimal string. That is, each pair of hexadecimal characters in the input string is decoded into the byte value that they represent, and that byte value is appended to a byte array which is ultimately returned. This function doesn't care whether the hexadecimal characters are upper or lower case, and it also can handle odd-length hex strings by assuming a leading zero digit. If any character in the input string is not a valid hexadecimal digit, it throws a NumberFormatException, in keeping with the behavior of Java functions like Integer.parseInt().

Parameters:

hexString - a string of hexadecimal characters

Returns:

a byte array built from the bytes indicated by the input string

Throws:

java.lang.NumberFormatException