1 Mail Application

Below is the source code for the Mail class:

package mail;
                                                                           
import java.util.Date;
                                                                           
import javax.naming.InitialContext;
                                                                           
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.Message;
import javax.jms.TextMessage;
import javax.jms.QueueSender;
import javax.jms.QueueSession;
import javax.jms.QueueReceiver;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
                                                                           
/**
   This class ilustrates a very simple mail application, which can
   read and send mail messages.
 */
                                                                           
public class Mail
{
    public static void main(String[] args) throws Exception
    {
    |   // create sender and receiver
    |   InitialContext ctx = new InitialContext();
    |   QueueConnectionFactory factory = (QueueConnectionFactory)
    |       ctx.lookup("queue/connectionFactory");
    |   Queue queue = (Queue) ctx.lookup("queue/queue0");
    |   QueueConnection conn = factory.createQueueConnection();
    |   QueueSession session = conn.createQueueSession(false,
    |       Session.AUTO_ACKNOWLEDGE);
    |   conn.start();
    |                                                                      
    |   // first arg is recipient, second arg is message
    |   if (args.length == 2)
    |   {
    |   |   QueueSender sender = session.createSender(queue);
    |   |   TextMessage msg = session.createTextMessage(args[1]);
    |   |   msg.setStringProperty("sender", System.getProperty("user.name"));
    |   |   msg.setStringProperty("to", args[0]);
    |   |   msg.setStringProperty("date", new Date().toString());
    |   |   sender.send(msg);
    |   }
    |   else
    |   {
    |   |   String selector = "to = '" + System.getProperty("user.name") + "'";
    |   |   QueueReceiver receiver = session.createReceiver(queue, selector);
    |   |   TextMessage msg = (TextMessage) receiver.receive(500);
    |   |   if (msg != null)
    |   |   {
    |   |   |   System.out.println("From: " + msg.getStringProperty("sender"));
    |   |   |   System.out.println("To: " + msg.getStringProperty("to"));
    |   |   |   System.out.println("Date: " + msg.getStringProperty("date"));
    |   |   |   System.out.println("\n" + msg.getText());
    |   |   }
    |   |   else
    |   |   {
    |   |   |   System.out.println("no messages");
    |   |   }
    |   }
    }
}
                                                                           

1. The recipient. This is the user name of the receiver of the message.
2. The message itself. This is a short text string with the mail message.

    "to = '" + System.getProperty("user.name") + "'";