Get MD5 String from Message Digest

Question

I understand how it works but if I want to print out the MD5 as String how would I do that?

public static void getMD5(String fileName) throws Exception{
            


        

Answer 1

First you need to get the byte[] output of the MessageDigest:

byte[] bytes = hash.digest();

You can't easily print this though (with e.g. new String(bytes)) because it's going to contain binary that won't have good output representations. You can convert it to hex for display like this however:

StringBuilder sb = new StringBuilder(2 * bytes.length);
for (byte b : bytes) {
    sb.append("0123456789ABCDEF".charAt((b & 0xF0) >> 4));
    sb.append("0123456789ABCDEF".charAt((b & 0x0F)));
}
String hex = sb.toString();