How to make Client instantly recieve msg from Server

Question

Hello! I'm trying to make a multiplayer game via Bluetooth (RFCOMM protocol) in J2ME. I already managed to detect devices both as a client and as a server. I also managed to send real-time message from client(s) to server in the following way:
// Pauses thread until Transmission occurs
StreamConnection conn = notifier.acceptAndOpen();
read_msg(conn); //this is the function which reads the date received from client
But when I try the above as a client I got some exception, but never mind actually.
Here is the actual problem:
I want to be able to send a message from server to client whenever I press a key so that the client instantly receives that message.
Now the only thing that comes to my mind is to periodically check (i.e. every 50 ms) StreamConnection and watch for some changes like this.
while(true) {
InputStream input = conn.openInputStream(); // conn is of type StreamConnection
//now I check if the messege received is the new one OR have I actually received a message
// here I pause the Thread for i.e. 60 ms
But that would be extremely CPU heavy and foolish, wouldn't it?
So is there a smart way to register when client gets a message from server?
Please give me some example for client side.
Edited by: leden on Sep 27, 2007 3:07 PM

Answer 1

One more question.
I have a server and many clients. Let's say I had already received the first message from every client with this piece of code:
for(int current_client = 0; current_client < MAX_CLIENTS; ++current_client) {
//notifier is of type StreamConnectionNotifier
StreamConnection conn = notifier.acceptAndOpen(); //wait for transmission to occur
String response = read_msg(conn); //read_msg actually reads the message
Now, at some other moment I want to send a message to one of the clients .
How could I do that?
Do I have to add this command in the for loop above, perhaps?:
conn_client[current_client] = conn;
then simply reply by doing:
OutputStream output = conn_list[who_I_want_to_send_msg_to].openOutputStream();
and then the code like in my first post
OR this whole procedure is totally wrong?
Please explaim me what does openOutputStream() actually do?
Edited by: leden on Sep 30, 2007 8:51 AM