WMA

• The WMA profile can be used in the CLDC configuration
• It allows the application to send and receive SMS and CBS messages

SMS Connection

• The wireless classes are in package javax.wireless.messaging
• SMS messages are sent using Connector objects, the same as any other communication
• SMS messages can be sent just to a phone number: in that case the phone handles the message. To send to a midlet, you must also specify the port number for that midlet
• The URL for a client sending a message to the midlet with phone number 1234567 on port 5432 is

  
        "sms://+1234567:5432"

  for telephone number 1234567
• The URL for an SMS server to receive messages on port 5432 is

  
        "sms://:5432"
        

SMS Client

Send a message by

      String address = "sms://+1234567:5432";
      String msg = "Hello";
      MessageConnection smsconn = 
             (MessageConnection) Connector.open(address);
      TextMessage txtmessage = (TextMessage)smsconn.newMessage(
                MessageConnection.TEXT_MESSAGE);
      txtmessage.setPayloadText(msg);
      smsconn.send(txtmessage)

SMS Server

try {
    String addr =  "sms://:5432";
    MessageConnection conn = (MessageConnection) Connector.open(addr);
    Message msg = null;
    while (someExitCondition) {
        // wait for incoming messages
        msg = conn.receive(); // received a message
        if (msg instanceof TextMessage) {
            TextMessage tmsg = (TextMessage) msg;
            String receivedText = tmsg.getPayloadText();
            // respond with the same text with  Received:
            // inserted in the beginning
            tmsg.setPayloadText("Received: " + receivedText);
            // Note that the recipient address in the message is
            // already correct as we are reusing the same object
            conn.send(tmsg);
        } else {
            // Received message was not a text message, but e.g. binary ...
        }
    }
} catch (Exception e) {
    ...
}

Emulator phone numbers

• The emulator's are assigned phone numbers in order of starting
• The first emulator has number 555 0000, the second has number 555 0001, etc
• This can also be set by adding a property to the emulator

  
        emulator -Dwma.client.phoneNumber=1234567 ...
        

Complete client

Complete server

Send and receive

• A client connection can only send. A server connection can send and/or receive
• If you want two-way communication between two phones, both have to set up an SMS server
• If a server wants to initiate sending, it must set the destination address in the message
• If a server wants to reply to a message it has received, it can just send back a message using the connection it received the message on

Send and receive client

Receive and send server