十六进制字符串和byte数组的相互转化

public static String getHexString(byte[] b) throws Exception {
String result = "";
for (int i=0; i < b.length; i++) {
result += Integer.toString( ( b[i] & 0xff ) + 0x100, 16).substring( 1 );
}
return result;
}

public static byte[] getByteArray(String hexString) {
return new BigInteger(hexString,16).toByteArray();
}