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Add dependency to either org.apache.wicket:wicket-native-websocket-jetty9, org.apache.wicket:wicket-native-websocket-jetty, or org.apache.wicket:wicket-native-websocket-tomcat.
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Setup the custom WicketFilter implementation for the chosen web container in your web.xml.
For Jetty 9.0+ this is
<filter-class>org.apache.wicket.protocol.ws.jetty9.Jetty9WebSocketFilter</filter-class>
For Jetty 7.5+ - 8.x this is
<filter-class>org.apache.wicket.protocol.ws.jetty7.Jetty7WebSocketFilter</filter-class>
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