Sockets in MIDP 1.0

[humberto@net-people.com]

Hi

Im developing a J2ME Chat client and im using MIDP 1.0. I know that Socket connections are not implemented in MIDP 1.0 specifications. Of course if somebody try to compile a code with Socket object, it doesnt compile.

Well for that reason im trying to use a Connector(url) and a StreamConnection. Something like this:

try {

String url = "socket://" + "200.74.214.103" + ":" + "6660";
StreamConnection s = (StreamConnection)

Connector.open(url);

Client( s); //manage messages in s

}
catch (IOException ioe) {

exception(ioe);
}

For me is another way to connect a chat server. I test the program in a different emulators (J2ME wireless toolkit, nokia emulator 60 series, palm emulator, motorola emulator) and it works. But if i run the program in a handset for example Nokia 3650 for GPRS, GTRAN phone, it doesnt work. Now i dont now if the problem is with the code or the implementation of gateways (celular network).

Somebody can tell me if there is something wrong? I can use that in MIDP 1.0? Is there another way to do that, some suggestions?

Thanks a lot.

[rscl]

You are in same problem as I am. Emulators works fine but actual mobile phone don't work because MIPD requires only HTTP support (And current Nokia phones doesn't support sockets).

When I try to connect to server, I get IOException, which says:

"The requested protocol does not exist socket://servernameort"

(servername and port containing correct name and port)..

I have tried to run this whit Nokia 6100...


-Hannu B.

[rscl]

.. An idea...

One way to oevercome this is to use HTTP gateway, simple Java or C/C++ program running on server which accepts your chat client connections and then forwards them to correct server and port whit _real_ sockets. Personally i don't like this because this make application server dependable. And if someone messes up in your chat it's not possible to trace up who did.. But this could work..

-Hannu B.

[bvolk]

It (gateway) does. We use that in our own product.

One benifit is that it can be used to reduce the size of the packets and even deal with phone disconnects in a more robust manner.

[RogerJFX]

If you're about to write your own Socket-Server, it shouldn't be a problem to handle with Http-headers.

[maffeis]

The good news is that "socket:" type StreamConnections actually do work on the 3650. One thing you should avoid, though, is reading and writing from/to the same SocketConnection in two different threads. This will actually freeze your MIDlet. (I tested that on a Nokia 3650, Firmware V. 3.16). silvano