The first thing that leapt into my mind was that this fits fairly well into the Pub/Sub paradigm. Clients publish chat messages to specific channels (rooms,) and also subscribe to the channels; the server subscribes to a channel and stores the data in a MySQL database.
You might try using an external real-time network like PubNub. PubNub is free for up to 1m messages (see the pricing page.) They have an Android SDK and PHP SDK (I assume you're using PHP on your server due to your use of the PHP tag.)
In your case, in your Android client, you'd subscribe to a channel:
Pubnub pubnub = new Pubnub("demo", "demo");
try {
pubnub.subscribe("my_channel", new Callback() {
//See full example for all Callback methods
@Override
public void successCallback(String channel, Object message) {
System.out.println("SUBSCRIBE : " + channel + " : "
+ message.getClass() + " : " + message.toString());
}
}
} catch (PubnubException e) {
System.out.println(e.toString());
}
(Full example here.) Then, when you want to publish a message:
Callback callback = new Callback() {
public void successCallback(String channel, Object response) {
Log.d("PUBNUB",response.toString());
}
public void errorCallback(String channel, PubnubError error) {
Log.d("PUBNUB",error.toString());
}
};
pubnub.publish("my_channel", "This is an important chat message!" , callback);
Neat! But what about your server, how does it receive these messages?
$pubnub = new Pubnub(
"demo", ## PUBLISH_KEY
"demo", ## SUBSCRIBE_KEY
"", ## SECRET_KEY
false ## SSL_ON?
);
$pubnub->subscribe(array(
'channel' => 'my_channel', ## REQUIRED Channel to Listen
'callback' => function($message) { ## REQUIRED Callback With Response
## Time to log this to MySQL!
return true; ## Keep listening (return false to stop)
}
));
I hope this helps your project. Let me know how it goes.