is it any simpler way then cometd as long-polling framework for java? Because what I need - is client specifies some parameters and sends them to server. Server process them and starts contonuously pushing messages back to client (looks like Thread-per-Service?). Client receivs messages and displays them. Client has possibility to stop listening and actually stop server's service to send messages. Maybe I'm too lazy, but cometd's examle was not that short and transparent as I wanted it to be.
Not HTML5 based.