title: Hot to catch a websocket-close event when client changes IP address or disconnects?
body: <p>I'm developing an application using web-sockets. The server side is written in Java and uses Netty as application framework, while the client is written in javascript/jquery. I'd like to catch any kind of client disconnection, but actually I can do that only when the client goes to a different website or just reload the page of the application. Contrary, if clients changes IP on-the-fly or disables the network interface (wireless or ethernet), the close event is only caught by client, but not server. Is there a way to catch also this kind of close event without using ping messages?</p>