@Override public void onHandshakeResponse(UpgradeResponse response) { resp.setStatus(response.getStatusCode()); for (String header : response.getHeaderNames()) { switch (header.toLowerCase()) { case "connection": case "date": case "sec-websocket-accept": case "upgrade": continue; } for (String value : response.getHeaders(header)) { resp.addHeader(header, value); } } try { wsFactory.acceptWebSocket(req, resp); } catch (IOException e) { throw new RuntimeException(e); } async.complete(); } });