/****************************************************************************** * Mail4ME - Mail for the Java 2 Micro Edition * * A lightweight, J2ME- (and also J2SE-) compatible package for sending and * receiving Internet mail messages using the SMTP and POP3 protocols. * * Copyright (c) 2000-2002 J鰎g Pleumann <joerg@pleumann.de> * * Mail4ME is part of the EnhydraME family of projects. See the following web * sites for more information: * * -> http://mail4me.enhydra.org * -> http://me.enhydra.org * * Mail4ME is distributed under the Enhydra Public License (EPL), which is * discussed in great detail here: * * -> http://www.enhydra.org/software/license/index.html * * Have fun! ******************************************************************************/package de.trantor.mail.demo.list;import de.trantor.mail.*;/** * Implements a very tiny mailing list processor. This class has been used in * the Dr. Dobbs 06/2002 article about Mail4ME. */public class MailingList {        static String pop3Host = "pop.yourisp.com";    static String pop3User = "user0815";    static String pop3Pass = "secret";        static String smtpHost = "smtp.yourisp.com";        static String listMachine = "localhost";    static String listOwner = "owner@yourlist.com";        static String[] users = {"duke@sun.com", "clippy@microsoft.com"};        static boolean isValidUser(Message message) throws Exception {        String sender = message.getHeaderValue("From");                sender = Message.getMachineAddress(sender).toLowerCase();                for (int i = 0; i < users.length; i++) {            if (users[i].equals(sender)) return true;        }                return false;    }        static void badMessage(Message message, String reason) throws Exception {        String sender = message.getHeaderValue("From");                Message reply = new Message(listOwner, sender, "Error");        reply.addBodyLine("Sorry, " + Message.getDisplayAddress(sender));        reply.addBodyLine("");        reply.addBodyLine("your message could not be delivered because");        reply.addBodyLine(reason);        reply.addBodyLine("");        reply.addBodyLine("Regards, " + listOwner);                SmtpClient smtp = new SmtpClient(listMachine);        smtp.open(smtpHost);        smtp.sendMessage(reply);        smtp.close();    }        static void goodMessage(Message message) throws Exception {        Envelope envelope = new Envelope(message, false);        envelope.setSender(listOwner);                for (int i = 0; i < users.length; i++) {            envelope.addRecipient(users[i]);        }                SmtpClient smtp = new SmtpClient(listMachine);        smtp.open(smtpHost);        smtp.sendMessage(envelope);        smtp.close();    }        static boolean isTextOnly(MimeDecoder mime) {        int count = mime.getPartCount();                if (count != 0) {            for (int i = 0; i < count; i++) {                if (!isTextOnly(mime.getPart(i))) return false;            }        }        else {            if (!mime.getType().toLowerCase().equals("text/plain")) return false;        }                return true;    }        public static void main(String[] args) throws Exception {        Pop3Client pop3 = new Pop3Client();        pop3.open(pop3Host, pop3User, pop3Pass);                for (int i = 0; i < pop3.getMessageCount(); i++) {            Message message = pop3.getMessage(i);                        if (!isValidUser(message)) {                badMessage(message, "you are not subscribed to the list.");            }            else if (!isTextOnly(new MimeDecoder(message))) {                badMessage(message, "the list allows plain text messages only.");            }            else {                goodMessage(message);            }                        pop3.removeMessage(i);        }                pop3.close();    }}