The simplest way can be –
private static final String HMAC_SHA512 = "HmacSHA512";
private static String toHexString(byte[] bytes) {
Formatter formatter = new Formatter();
for (byte b : bytes) {
formatter.format("%02x", b);
}
return formatter.toString();
}
public static String calculateHMAC(String data, String key)
throws SignatureException, NoSuchAlgorithmException, InvalidKeyException
{
SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(), HMAC_SHA512);
Mac mac = Mac.getInstance(HMAC_SHA512);
mac.init(secretKeySpec);
return toHexString(mac.doFinal(data.getBytes()));
}
public static void main(String[] args) throws Exception {
String hmac = calculateHMAC("data", "key");
System.out.println(hmac);
}
You can change the HMAC_SHA512 variable to any of the Mac algorithm and the code will work the same way.