Intercepting WebSocket ping messages

[Robert Lewis]

Is there a way to intercept a ping message to send a pong? I need to do
this synchronize sends to the endpoint.

I tried

        session.addMessageHandler(new
javax.websocket.MessageHandler.Whole<PongMessage>() {

            @Override
            public void onMessage(PongMessage message) {
                System.out.println("hi");
            }

        });


And

@OnMessage public void onPong(PongMessage message) {}