This is how you hide the server version in Jetty 8:
Server server = new Server(port);
server.setSendServerVersion(false);
How do you do it
Lambda-style variant of Jacob's solution (which worked for me):
final Server server = new Server(port);
Stream.of(server.getConnectors()).flatMap(connector -> connector.getConnectionFactories().stream())
.filter(connFactory -> connFactory instanceof HttpConnectionFactory)
.forEach(httpConnFactory -> ((HttpConnectionFactory)httpConnFactory).getHttpConfiguration().setSendServerVersion(false));