Callback is not received when network is poor and connection is terminated from other End

[ManuKow]

When we have used the library to connect to an backend and the signal strength is very poor and the backend has terminated the connection, we do not get call back
this.socket.setClosedCallback(new CompletedCallback() {
public void onCompleted(Exception var1) {
}
});

[Th0rum]

https://github.com/websockets/ws#how-to-detect-and-close-broken-connections
you need to detect it by yourself, this is called ping pong / heartbeat method, where you send frequent packet e.g every 10 second and if the client does not reply in e.g 5 second you terminate the connection. I hope this help other ppl aswell.