Java md5sum

import java.io.File;
import java.io.FileInputStream;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.security.MessageDigest;

public class Md5sum {
  public static void main(String[] args) throws Exception {
    File file = new File(args[0]);
    MessageDigest md = MessageDigest.getInstance("md5");
    ByteBuffer buff = ByteBuffer.allocate(1024);
    FileInputStream in = new FileInputStream(file);
    try {
      FileChannel fcin = in.getChannel();
      while (fcin.read(buff) != -1) {
        buff.flip();
        md.update(buff);
        buff.clear();
      }
      fcin.close();
    } finally {
      in.close();
    }

    byte[] digest = md.digest();
    BigInteger bi = new BigInteger(1, digest);
    System.out.printf("%0" + (digest.length << 1) + "x %s", bi, file);
  }
}