#1. Socket Prgrmming | MailClient Source Code.

// Envelope.java

import java.io.*;

import java.net.*;

import java.util.*;

/*MY INFO  */

/**

 * @author Alek amodi@clunet.edu

 * 

 *         Using Cal Lutheran Local Mailserver and port number this app can send

 *         and process SMT Protocol.

 * 

 *         To: Dr. Chu

 */

/*

 * Developed on - Sep 08, 2011

 * 

 * WireShark Lab work - MailClient

 */

public class Envelope {

/* SMTP-sender of the message (in this case, contents of From-header. */

public String Sender;

/* SMTP-recipient, or contents of To-header. */

public String Recipient;

/* Target MX-host */

public String DestHost;

public InetAddress DestAddr;

/* The actual message */

public Message Message;

/* Create the envelope. */

public Envelope(Message message, String localServer)

throws UnknownHostException {

/* Get sender and recipient. */

Sender = message.getFrom();

Recipient = message.getTo();

/*

* Get message. We must escape the message to make sure that there are

* no single periods on a line. This would mess up sending the mail.

*/

Message = escapeMessage(message);

/*

* Take the name of the local mail-server and map it into an InetAddress

*/

DestHost = localServer;

try {

DestAddr = InetAddress.getByName(DestHost);

} catch (UnknownHostException e) {

System.out.println("Unknown host: " + DestHost);

System.out.println(e);

throw e;

}

return;

}

/*

* Escape the message by doubling all periods at the beginning of a line.

*/

private Message escapeMessage(Message message) {

String escapedBody = "";

String token;

StringTokenizer parser = new StringTokenizer(message.Body, "\n", true);

while (parser.hasMoreTokens()) {

token = parser.nextToken();

if (token.startsWith(".")) {

token = "." + token;

}

escapedBody += token;

}

message.Body = escapedBody;

return message;

}

/* For printing the envelope. Only for debug. */

public String toString() {

String res = "Sender: " + Sender + '\n';

res += "Recipient: " + Recipient + '\n';

res += "MX-host: " + DestHost + ", address: " + DestAddr + '\n';

res += "Message:" + '\n';

res += Message.toString();

return res;

}

}