当在springcloud项目时候搭建springcloud -hystrix-dashboard ，如果父亲采用spring boot 2.0以上 一般需要在appliation加入注解

@Bean
    public ServletRegistrationBean getServlet() {
        HystrixMetricsStreamServlet streamServlet = new HystrixMetricsStreamServlet();
        ServletRegistrationBean registrationBean = new ServletRegistrationBean(streamServlet);
        registrationBean.setLoadOnStartup(1);
        registrationBean.addUrlMappings("/hystrix.stream");
        registrationBean.setName("HystrixMetricsStreamServlet");
        return registrationBean;
    }
}

如仅仅是以普通项目开头的则是无需加上版本