Unable to connect to Command Metric Stream.

学习Cloud搭建HystrixDashboard仪表盘中的小坑。由于Hystrix不更新的，所以2.2版本的Spring对它没做好兼容。要自己在生产者的启动类改造：

@SpringBootApplication
@EnableEurekaClient
@EnableDiscoveryClient
@EnableHystrix
@EnableCircuitBreaker
public class CirculateMain {
    
    
    public static void main(String[] args) {
    
    
        SpringApplication.run(CirculateMain.class, args);
    }

    @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;
    }

}