HexHarmless (HexUtils 1.0.0 API)

java.lang.Object
- net.lbruun.hexutils.HexHarmless

```
public class HexHarmless
extends Object
```
Utilities for converting to/from harmless hex characters.
Why harmless hex characters?
With the English language it is possible out of the hex characters (0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f) to form words that might be bad/funny/peculiar/offensive. The idea with harmless hex characters is to replace vowels and vowel-like hex characters with consonants, the theory being that in the English language it is near-impossible to form words solely out of consonants.
The following replacements are done:
```
 | ---- | ----------- |
 | char | replaced by |
 | ---- | ----------- |
 |  0   |    g        |
 |  1   |    h        |
 |  3   |    k        |
 |  a   |    m        |
 |  e   |    t        |
 | ---- | ----------- |
 
```
thus as an example, the classic hex encoded string of 0ffaeb would become gffmtb in harmless hex.
This docucters [2,4-9,b,c,d,f,g,h,k,m,t] as harmless hex chars. Harmless hex exists only in the lower-case variant.
The concept of harmless hex characters exists in Google's Kubernetes from where the character mapping in this class originates. (source code link, function encodeHash)

Field Summary

Fields
Modifier and Type	Field and Description
`static char[]`	`HARMLESS_HEX_CHARS` Characters allowed in harmless hex representation.
`static String`	`HARMLESS_HEX_REGEXP_CHARCLASS` Regular expression character set with the characters that are allowed in harmless hex representation.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static char[]`	`bytesToHexHarmless(byte[] bytes)` Converts a byte array to its harmless hexadecimal representation.
`static String`	`bytesToHexStrHarmless(byte[] bytes)` Converts a byte array to its harmless hexadecimal representation.
`static char[]`	`byteToHexHarmless(byte b)` Converts a single byte to its harmless hexadecimal representation.
`static char`	`convertFromHarmless(char c)` Returns classic hex char equivalent of the input harmless hex char.
`static char[]`	`convertFromHarmless(char[] chars)` Replaces harmless hex characters in the input array with their classic hex char equivalents.
`static char`	`convertToHarmless(char c)` Returns harmless equivalent of the input hex char.
`static char[]`	`convertToHarmless(char[] chars)` Replaces classic hex characters in the input array with their harmless equivalents.
`static byte`	`hexCharHarmlessToByte(char c1, char c2)` Converts a harmless hex character pair into a byte.
`static byte[]`	`hexStrHarmlessToBytes(char[] chars)` Converts a character array consisting of harmless hexadecimal characters into a byte array.
`static byte[]`	`hexStrHarmlessToBytes(CharSequence s)` Converts a character sequence (a string) consisting of harmless hexadecimal characters into a byte array.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - HARMLESS_HEX_REGEXP_CHARCLASS
```
public static final String HARMLESS_HEX_REGEXP_CHARCLASS
```
    Regular expression character set with the characters that are allowed in harmless hex representation.
    
    See Also:
    
    Constant Field Values
  - HARMLESS_HEX_CHARS
```
public static final char[] HARMLESS_HEX_CHARS
```
    Characters allowed in harmless hex representation.
- Method Detail
  - convertFromHarmless
```
public static char convertFromHarmless(char c)
```
    Returns classic hex char equivalent of the input harmless hex char. The input is expected to be a lower-case harmless hex char.
    
    Parameters:
    
    c - hex char
    
    Returns:
    
    harmless equivalent
    
    Throws:
    
    IllegalArgumentException - if input is not a lower-case harmless hex char
    
    See Also:
    
    convertToHarmless(char)
  - convertToHarmless
```
public static char convertToHarmless(char c)
```
    Returns harmless equivalent of the input hex char. The input is expected to be a lower-case classic hex char.
    
    Parameters:
    
    c - harmless hex char
    
    Returns:
    
    hex char equivalent
    
    Throws:
    
    IllegalArgumentException - if input is not a lower-case classic hex char
    
    See Also:
    
    convertFromHarmless(char)
  - convertToHarmless
```
public static char[] convertToHarmless(char[] chars)
```
    Replaces classic hex characters in the input array with their harmless equivalents. Note that the input array is altered by this method.
    
    Parameters:
    
    chars -
    
    Returns:
    
    Throws:
    
    IllegalArgumentException - if input array contains characters which are not lower-case classic hex char.
  - convertFromHarmless
```
public static char[] convertFromHarmless(char[] chars)
```
    Replaces harmless hex characters in the input array with their classic hex char equivalents. Note that the input array is altered by this method.
    
    Parameters:
    
    chars -
    
    Returns:
    
    Throws:
    
    IllegalArgumentException - if input array contains characters which are not lower-case harmless hex char.
  - byteToHexHarmless
```
public static char[] byteToHexHarmless(byte b)
```
    Converts a single byte to its harmless hexadecimal representation.
    See HexHarmless.
    
    Parameters:
    
    b - input
    
    Returns:
    
    char array of length 2
  - bytesToHexHarmless
```
public static char[] bytesToHexHarmless(byte[] bytes)
```
    Converts a byte array to its harmless hexadecimal representation.
    
    Parameters:
    
    bytes - input
    
    Returns:
    
    harmless hexadecimal representation
  - bytesToHexStrHarmless
```
public static String bytesToHexStrHarmless(byte[] bytes)
```
    Converts a byte array to its harmless hexadecimal representation.
    
    Parameters:
    
    bytes - input
    
    Returns:
    
    harmless hexadecimal representation
  - hexCharHarmlessToByte
```
public static byte hexCharHarmlessToByte(char c1,
                                         char c2)
```
    Converts a harmless hex character pair into a byte. For example the pair 't' and 'k' returns the byte value 227.
    The input values must be only the characters [4-9,b,c,d,f,m,t].
    
    Parameters:
    
    c1 - first character of pair
    
    c2 - second character of pair
    
    Returns:
    
    Throws:
    
    IllegalArgumentException - if either c1 or c2 is an illegal character.
  - hexStrHarmlessToBytes
```
public static byte[] hexStrHarmlessToBytes(char[] chars)
```
    Converts a character array consisting of harmless hexadecimal characters into a byte array.
    The input must be of equal-length and consist only of lower-case harmless hex chars.
    
    Parameters:
    
    chars - input
    
    Returns:
    
    byte array or null if input is null.
    
    Throws:
    
    IllegalArgumentException - if input array contains characters which are not lower-case harmless hex char.
  - hexStrHarmlessToBytes
```
public static byte[] hexStrHarmlessToBytes(CharSequence s)
```
    Converts a character sequence (a string) consisting of harmless hexadecimal characters into a byte array.
    The input must be of equal-length and consist only of lower-case harmless hex chars.
    
    Parameters:
    
    s - input
    
    Returns:
    
    byte array or null if input is null.
    
    Throws:
    
    IllegalArgumentException - if input sequence contains characters which are not lower-case harmless hex char.

Class HexHarmless

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

HARMLESS_HEX_REGEXP_CHARCLASS

HARMLESS_HEX_CHARS

Method Detail

convertFromHarmless

convertToHarmless

convertToHarmless

convertFromHarmless

byteToHexHarmless

bytesToHexHarmless

bytesToHexStrHarmless

hexCharHarmlessToByte

hexStrHarmlessToBytes

hexStrHarmlessToBytes