Groovy fileToMd5

def fileToMd5(File aFile) {
   def digest = java.security.MessageDigest.getInstance("MD5");
   aFile.withInputStream{ inpStream ->
       byte[] buffer = new byte[8192];
       int read      = 0;
       while( (read=inpStream.read(buffer)) > 0 ) {
           digest.update(buffer, 0, read);
       }
   }
   byte[] md5sumByteArray = digest.digest();
   def    bigInt          = new BigInteger(1, md5sumByteArray);
   return bigInt.toString(16).padLeft(32, '0');
}