@Override
public void init(FilterConfig filterConfig) throws ServletException {
ServletContext sc = filterConfig.getServletContext();
    WebApplicationContext cxt = WebApplicationContextUtils.getWebApplicationContext(sc);
    if(cxt != null) {
        if (publicService == null) {
            publicService = cxt.getBean(PublicService.class);
        }
    }
}

filter （过滤器）中注入service