import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
public class MainClass {
public static void main(String[] args) throws Exception {
String alg = "HmacMD5";
Mac mac = Mac.getInstance(alg);
KeyGenerator kg = KeyGenerator.getInstance(alg);
SecretKey key = kg.generateKey();
mac.init(key);
mac.update("test".getBytes());
byte[] b = mac.doFinal();
System.out.println(new String(b));
}
}