/**
* Mad-Advertisement
* Copyright (C) 2011 Thorsten Marx <thmarx@gmx.net>
*
* This program is free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
package net.mad.ads.common.code;
import java.util.UUID;
/**
* A collection of static utility methods to manipulate Base16-encoded data.
*
* <p>Base16 encoding uses two bytes with the ASCII values of 2 hexadecimal
* digits to represent one byte of data.
*
* <p><dl><dt><b>Maturity:</b><dd>
* Mature. Fixed API. Fully documented.
* Methods for encoding and decoding binary data should be added.
* </dl>
*
* @author Stefan Zeiger
* @see com.novocode.tk.util.Base64
*/
public final class Base16
{
/* Dummy constructor */
private Base16() {}
/**
* Encodes a Latin-1 string. The upper 8 bits are discarded.
*
* @param dec the string to be encoded.
* @return the Base16 code for the string.
* @see #decode
*/
public static String encode(String dec)
{
int l = dec.length();
StringBuffer enc = new StringBuffer(l*2);
for(int i=0; i<l; i++)
enc.append(enc_codes[(byte)(dec.charAt(i))]);
return enc.toString();
}
/**
* Encodes a byte array.
*
* @param dec the data to be encoded.
* @return the Base16 code for the data.
* @see #decodeBytes
*/
public static String encodeBytes(byte[] dec)
{
StringBuffer enc = new StringBuffer(dec.length*2);
for(int i=0; i<dec.length; i++) enc.append(enc_codes[dec[i] & 0xFF]);
return enc.toString();
}
/**
* Decodes a Latin-1 string.
*
* @param enc the Base16 code of a Latin-1 string.
* @return the decoded string.
* @see #encode
*/
public static String decode(String enc)
{
int l = enc.length();
StringBuffer dec = new StringBuffer(l/2);
for(int i=0; i<l; i+=2)
{
byte n, b;
b = (byte)(enc.charAt(i));
if((b>=(byte)('0')) && (b<=(byte)('9'))) n = (byte)(b-(byte)('0'));
else n = (byte)(b-(byte)('A')+10);
b = (byte)(enc.charAt(i+1));
if((b>=(byte)('0')) && (b<=(byte)('9')))
n = (byte)((n<<4) + b-(byte)('0'));
else n = (byte)((n<<4) + b-(byte)('A')+10);
dec.append((char)n);
}
return dec.toString();
}
/**
* Decodes a byte array.
*
* @param enc the Base16 code for the data.
* @return the decoded byte array.
* @see #encodeBytes
*/
public static byte[] decodeBytes(String enc)
{
int l = enc.length();
int i=0, j=0;
byte[] dec = new byte[l/2];
while(i<l)
{
byte n, b;
b = (byte)(enc.charAt(i));
if((b>=(byte)('0')) && (b<=(byte)('9'))) n = (byte)(b-(byte)('0'));
else n = (byte)(b-(byte)('A')+10);
b = (byte)(enc.charAt(i+1));
if((b>=(byte)('0')) && (b<=(byte)('9')))
n = (byte)((n<<4) + b-(byte)('0'));
else n = (byte)((n<<4) + b-(byte)('A')+10);
dec[j] = n;
i+=2;
j++;
}
return dec;
}
private static final String[] enc_codes =
{
"00","01","02","03","04","05","06","07",
"08","09","0A","0B","0C","0D","0E","0F",
"10","11","12","13","14","15","16","17",
"18","19","1A","1B","1C","1D","1E","1F",
"20","21","22","23","24","25","26","27",
"28","29","2A","2B","2C","2D","2E","2F",
"30","31","32","33","34","35","36","37",
"38","39","3A","3B","3C","3D","3E","3F",
"40","41","42","43","44","45","46","47",
"48","49","4A","4B","4C","4D","4E","4F",
"50","51","52","53","54","55","56","57",
"58","59","5A","5B","5C","5D","5E","5F",
"60","61","62","63","64","65","66","67",
"68","69","6A","6B","6C","6D","6E","6F",
"70","71","72","73","74","75","76","77",
"78","79","7A","7B","7C","7D","7E","7F",
"80","81","82","83","84","85","86","87",
"88","89","8A","8B","8C","8D","8E","8F",
"90","91","92","93","94","95","96","97",
"98","99","9A","9B","9C","9D","9E","9F",
"A0","A1","A2","A3","A4","A5","A6","A7",
"A8","A9","AA","AB","AC","AD","AE","AF",
"B0","B1","B2","B3","B4","B5","B6","B7",
"B8","B9","BA","BB","BC","BD","BE","BF",
"C0","C1","C2","C3","C4","C5","C6","C7",
"C8","C9","CA","CB","CC","CD","CE","CF",
"D0","D1","D2","D3","D4","D5","D6","D7",
"D8","D9","DA","DB","DC","DD","DE","DF",
"E0","E1","E2","E3","E4","E5","E6","E7",
"E8","E9","EA","EB","EC","ED","EE","EF",
"F0","F1","F2","F3","F4","F5","F6","F7",
"F8","F9","FA","FB","FC","FD","FE","FF"
};
public static void main (String... args) {
String test = "oiutoiut87-6597fgo87f8";
test = Base16.encode(test);
System.out.println(test);
test = Base16.decode(test);
System.out.println(test);
}
}