why can't I call .update on a MessageDigest instance

Question

when i run this from the repl:

(def md (MessageDigest/getInstance "SHA-1"))
(. md update (into-array [(byte 1)  (byte 2)  (byte 3)]))

I get:

No matching method found: update for class java.security.MessageDigest$Delegate

the Java 6 docs for MessageDigest show:

update(byte[] input) 
      Updates the digest using the specified array of bytes.

and the class of (class (into-array [(byte 1) (byte 2) (byte 3)])) is [Ljava.lang.Byte;

Am I missing something in the definition of update?
Not creating the class I think I am?
Not passing it the type I think I am?

Answer 1

Because you are calling update(Byte[]) which is not defined in MessageDigest. You need to convert it into primitive array.

You can do something like this,

 (defn updateBytes [#^MessageDigest md, #^bytes data] 
      (.update md data)) 

Answer 2

Try:

(. md update (into-array Byte/TYPE [(byte 1) (byte 2) (byte 3)]))