// MailNotifier.java by Rowland http://home.comcast.net/~rowland3/
// uses JavaMail to send a message

// NOTE: Needs mail.jar and activation.jar in CLASSPATH to run
//       Needs mail.jar to compile

import javax.mail.Address;
import javax.mail.Message;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.net.InetAddress;
import java.util.Properties;

/** MailNotifier - a utility class to send a SMTP mail notification **/
public class MailNotifier {
    final String localhost;
    final String mailhost;
    final String mailuser;
    final String email_notify;
    protected Session session= null;

    public MailNotifier(String _localhost, String _mailhost, String _mailuser, String _email_notify) {
	localhost= _localhost;
	mailhost= _mailhost;
	mailuser= _mailuser;
	email_notify= _email_notify;
    }

    public void send(String subject, String text)  throws Exception {
	send(email_notify, subject, text);
    }
    public void send(String _to, String subject, String text)  throws Exception {
	if (session== null) {
	    Properties p = new Properties();
	    p.put("mail.host", mailhost);
	    p.put("mail.user", mailuser);
	    session = Session.getDefaultInstance(p, null);

	    // Try to fake out SMTPTransport.java and get working EHLO:
	    Properties properties = session.getProperties();
	    String key= "mail.smtp.localhost";
	    String prop= properties.getProperty(key);
	    if (prop== null)   properties.put(key, localhost);
	    else  System.out.println(key+ ": "+ prop);

	    //session.setDebug(true);
	}
	MimeMessage msg = new MimeMessage(session);
	msg.setText(text);
	msg.setSubject(subject);
	Address fromAddr = new InternetAddress(mailuser);
	msg.setFrom(fromAddr);
	Address toAddr = new InternetAddress(_to);
	msg.addRecipient(Message.RecipientType.TO, toAddr);       
	Transport.send(msg);
	// Note: will use results of getLocalHost() to fill in EHLO domain
    }

    /**
     * Get the name of the local host, for use in the EHLO and HELO commands.
     * The property mail.smtp.localhost overrides what InetAddress would tell
     * us.
      Adapted from SMTPTransport.java
     */
    public String getLocalHost() {
	String localHostName= null;
	String name = "smtp";	// Name of this protocol
	try {
	    // get our hostname and cache it for future use
	    if (localHostName == null || localHostName.length() <= 0)
		localHostName =	session.getProperty("mail." + name + ".localhost");
	    if (localHostName == null || localHostName.length() <= 0)
		localHostName = InetAddress.getLocalHost().getHostName();
	} catch (Exception uhex) {
	}
	return localHostName;
    }

    /** main() for testing pursposes **/
    public static void main(String args[]) {
	// Adapt to your needs:
	String localhost= "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.com";
	String mailhost= "smtp.comcast.net";
	String mailuser= "MailNotifier_test@comcast.net";
	String email_notify= "XXXXXXX@comcast.net";

	MailNotifier mn= new MailNotifier(localhost, mailhost, mailuser, email_notify);
	try {
	    mn.send("Test", "Test body from MailNotifier.java main()");
	} catch (Exception E) {
	    System.err.println(E.toString());
	}
    }
}