converting between byte arrays and hex encoded strings
public class HexCodec { private static final char[] kDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; public static char[] bytesToHex(byte[] raw) { int length = raw.length; char[] hex = new char[length * 2]; for (int i = 0; i < length; i++) { int value = (raw[i] + 256) % 256; int highIndex = value >> 4; int lowIndex = value & 0x0f; hex[i * 2 + 0] = kDigits[highIndex]; hex[i * 2 + 1] = kDigits[lowIndex]; } return hex; } public static byte[] hexToBytes(char[] hex) { int length = hex.length / 2; byte[] raw = new byte[length]; for (int i = 0; i < length; i++) { int high = Character.digit(hex[i * 2], 16); int low = Character.digit(hex[i * 2 + 1], 16); int value = (high << 4) | low; if (value > 127) value -= 256; raw[i] = (byte) value; } return raw; } public static byte[] hexToBytes(String hex) { return hexToBytes(hex.toCharArray()); } }