I managed to create a WebSocketHandler using the Spring 5 Reactive WebSocket support (Chapter 23.2.4). Receiving and sending all works fine. However, I can not figure out how to detect a client disconnect. When debugging a client disconnect it somewhere stops at the server side in the HttpServerWSOperations class (netty.http.server package), where it does detect a CloseWebSocketFrame.
Any suggestions how to deal with client disconnects?