If for some reason you need to fully refresh current JSF page, in your action you can use code like:
FacesContext context = FacesContext.getCurrentInstance();
String viewId = context.getViewRoot().getViewId();
ViewHandler handler = context.getApplication().getViewHandler();
UIViewRoot root = handler.createView(context, viewId);
root.setViewId(viewId);
context.setViewRoot(root);
Or if your page doesn’t get refreshed due to browser caching, you can set appropriate headers to response in PhaseListener, RENDER_RESPONSE phase:
response.setHeader("Cache-Control", "no-cache");
response.setHeader("Pragma", [...]
