MD5 checksum, can i do this faster , from a inputstream ?

[Frank Jacobsen]

I calculate a MD5 checksum, from a inputstream, but with this code i read the 1 mb data to calculate the MD5......

Its not allsays 1 mb, it can be from 50 kb ---> 50 mb

Is there anyone, that knows if i can do this faster.....

  

java.security.MessageDigest md5er =    MessageDigest.getInstance("MD5");
        
	        byte[] buf = new byte[8192];
			int num = 0;
			int i = 1;
			
			num = connection.getInputStream().read(buf);
			while (num > 0) {
					
					md5er.update(buf,0,buf.length);
					System.out.println("FJA: " + i);
					length = length + buf.length;
					i++;
					num = connection.getInputStream().read(buf);
					
			}
			byte[] md5sum = md5er.digest();
			BigInteger bigInt = new BigInteger(1, md5sum);
			String output = bigInt.toString(16);
			System.out.println("FJA length: " + length);
			System.out.println("MD5: " + output);

Frank

[Rob Prime]

md5er.update(buf,0,buf.length);
...
length = length + buf.length;

Don't use buf.length but num. num can be smaller than buf.length if there weren't enough bytes available. This way you may write some garbage of a previous read to the MD5 digest, and your length may be too high.