/* * Copyright (c) 2003-onwards Shaven Puppy Ltd * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * * Neither the name of 'Shaven Puppy' nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package net.puppygames.gamecommerce.shared; /** * A utility class to decode hexadecimal numbers from strings into byte arrays, * such as those produced by HexEncoder. */ public abstract class HexDecoder { /** No construction */ private HexDecoder() {} /** * Decode a string of hex into a byte array. The string must of course be * even in length as each pair of digits makes one byte. * @param in The input String * @return byte[], or null, if in is null * @throws IllegalArgumentException if the String is not even-length * @throws NumberFormatException if the String does not contain only hex digits */ public static byte[] decode(String in) throws IllegalArgumentException, NumberFormatException { if (in == null) { return null; } if ((in.length() & 1) == 1) { throw new IllegalArgumentException("Input string must be an even length."); } byte[] ret = new byte[in.length() >> 1]; for (int i = 0; i < ret.length; i ++) { ret[i] = (byte) Integer.parseInt(in.substring(i * 2, i * 2 + 2), 16); } return ret; } }