This is how you hide the server version in Jetty 8:
Server server = new Server(port);
server.setSendServerVersion(false);
How do you do it
There is now an HttpConfiguration object with that setting on it.
org.eclipse.jetty.server.HttpConfiguration
Look to the jetty.xml for the section on http configuration section showing how to setup the object and then the jetty-http.xml file which shows how that configuration is used. Remember that the jetty xml files are really just a thin skin over java and work basically the same.
http://git.eclipse.org/c/jetty/org.eclipse.jetty.project.git/tree/jetty-server/src/main/config/etc/jetty.xml
http://git.eclipse.org/c/jetty/org.eclipse.jetty.project.git/tree/jetty-server/src/main/config/etc/jetty-http.xml