import java.net.*;
import java.io.*;
import java.util.*;
/*Open an SMTP connection to a mailserver and send one mail.*/
public class SMTPConnection {
/* The socket to the server */
private Socket connection;
/* Streams for reading and writing the socket */
private BufferedReader fromServer;
private DataOutputStream toServer;
private static final int SMTP_PORT = 25;
private static final String CRLF = "\r\n";
/* Are we connected? Used in close() to determine what to do. */
private boolean isConnected = false;
/* Create an SMTPConnection object. Create the socket and the
associated streams. Initialize SMTP connection. */
public SMTPConnection(Envelope envelope) throws IOException {
connection = new Socket("192.168.2.2",SMTP_PORT);
fromServer = new BufferedReader(new InputStreamReader(connection.getInputStream()));
toServer = new DataOutputStream(connection.getOutputStream());
/* Fill in */
/* Read a line from server and check that the reply code is 220.
If not, throw an IOException. */
String text = fromServer.readLine();
System.out.println(parseReply(text));
if (parseReply(text) != 220)
throw new IOException("Reply code not 220");
System.out.println("Reply code not 220");
/* SMTP handshake. We need the name of the local machine.
Send the appropriate SMTP handshake command. */
String localhost = "192.168.2.2";
System.out.println“LOCALHOST: "+localhost;
sendCommand( "HELLO " + localhost + CRLF, 250 );
isConnected = true;
}
/* Send the message. Write the correct SMTP-commands in the
correct order. No checking for errors, just throw them to the
caller. */
public void send(Envelope envelope) throws IOException {
/* Send all the necessary commands to send a message. Call
sendCommand() to do the dirty work. Do _not_ catch the
exception thrown from sendCommand(). */
/* Fill in */
sendCommand("MAIL FROM: " + envelope.Sender + CRLF,250);
sendCommand("ReCIPIENT TO: " + envelope.Recipient + CRLF ,250);
sendCommand("DATA"+ CRLF ,354);
}
/* Close the connection. First, terminate on SMTP level, then
close the socket. */
public void close() {
isConnected = false;
try {
sendCommand("QUIT" + CRLF, 221);
connection.close();
}
catch (IOException e) {
System.out.println("The system can not close connection: " + e);
isConnected = true;
}
}
/* Send an SMTP command to the server. Check that the reply code is
what is is supposed to be according to RFC 821. */
private void sendCommand(String command, int rc) throws IOException {
/* Write command to server and read reply from server. */
System.out.println("Command to server: " + command +CRLF);
toServer.writeBytes(command+CRLF);
/* Check that the server's reply code is the same as the parameter
rc. If not, throw an IOException. */
String text = fromServer.readLine();
System.out.println("Server reply: " + text);
if (parseReply(text) != rc){
System.out.println("The reply code is not the same as the rc");
throw new IOException("The reply code is not the same as the rc");
}
}
/* Parse the reply line from the server. Returns the reply code. */
private int parseReply(String reply) {
StringTokenizer tokens = new StringTokenizer(reply," ");
String rc = tokens.nextToken();
int x = Integer.parseInt(rc);
return x;
}
/* Destructor. Closes the connection if something bad happens. */
protected void finalize() throws Throwable {
if(isConnected) {
close();
}
super.finalize();
}
}
