@ServerEndpoint(value = "/endpoint", configurator = SocketConfigurator.class, encoders=WsEncoder.class, decoders=WsDecoder.class)
public class WsEndpoint {

    private static final Logger LOGGER = LogManager.getLogger(WsEndpoint.class);

    private static final CopyOnWriteArrayList<WsUser> wsWebUsers = new CopyOnWriteArrayList<WsUser>();

    public WsEndpoint() {
        LOGGER.info("ENDPOINT CREATED");
    }

    @OnOpen
    public void onOpen(Session session) {
        LOGGER.info("ENDPOINT ONOPEN");
    }

    @OnMessage
    public void onMessage(Session session, WsMessage wsMessage) {

        new WsOnMessage(session, wsMessage);

    }

    @OnClose
    public void onClose(Session session) {

    }

    @OnError
    public void onError(Session session, Throwable ex) {
        LOGGER.error("ENDPOINT ERROR", ex);
    }

    private class WsOnMessage {

        private Session session;
        private WsMessage wsMessage;

        public WsOnMessage(Session session, WsMessage wsMessage) {
            this.session = session;
            this.wsMessage = wsMessage;

            call();

        }

        private void call() {
            switch (wsMessage.getType()) {
                ...
            }
        }

    }

}

session.addMessageHandler(new MessageHandler.Whole<WsMessage>() {
            @Override
            public void onMessage(WsMessage wsMessage) {

            }
        });

@OnMessage
    public void onMessage(Session session, WsMessage wsMessage) {

    }