attachments to e-mail?

I've got something like the following...

   public boolean sendmail (String host, String to, String from,
String message, String subject, String开发者_高级运维 cc){
      try
      {
         //Created TCP Connection to server
         Socket s = new Socket(host, 25);
         //Open our streams.
         InputStream inStream = s.getInputStream();
         OutputStream outStream = s.getOutputStream();
         in = new Scanner(inStream);
         out = new PrintWriter(outStream, true );
         //get my info!
         String hostName = InetAddress.getLocalHost().getHostName();
         //e-mail time!

         receive();
         send("HELO" + host);
         receive();
         send("MAIL FROM: <" + from + "\n");
         receive();
         send("RCPT TO: <" + to + "\n");
         receive();
         send("DATA");
         receive();
         send("DATA");
         receive();
         //Make sure to close the everything again!!
         out.close();
         in.close();
         s.close();
         return true;
      }
      catch (Exception e)
      {
          appendtolog("ERROR: " + e);
          return false;
      }
   }

private void send(String s) throws IOException{
    appendtolog(s);
    out.print(s.replaceAll("\n", "\r\n"));
    out.print("\r\n");
    out.flush();
}

private void receive(){
    String line = in.nextLine();
    appendtolog(line);
}

is it possible to just put an attachment somewhere in there? I realise there is ways of doing this using the API more but I'm wondering there a way I can hammer functionality for attachments into that or is using something like..

// Set the email attachment file
MimeBodyPart attachmentPart = new MimeBodyPart();
FileDataSource fileDataSource = new FileDataSource(filename) {
@Override
public String getContentType() {
  return "application/octet-stream"; 
}
 };
 attachmentPart.setDataHandler(new DataHandler(fileDataSource));
  attachmentPart.setFileName(filename);

I would recommend going back to basics and read the RFCs on this.

Internet Message Format http://www.faqs.org/rfcs/rfc2822.html

Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies http://www.faqs.org/rfcs/rfc2045.html

These are more or less straight forward, there is some arcane stuff in there but you should be able to suss out what you need.

I would suggest trying to separate the communication (which you've got above) with the body (message content) as much as possible, else you'll muddy the waters.

Hope that helps.

It is obviously possible, but I'd suggest you to use JavaMail API instead of dealing with gory details of SMTP protocol. It is correct unless you are implementing a student exercise.