在我们Eureka Server 的微服务中，可以通过增加以下事件监听器来实现对其他微服务的上线和下线监听

@Component
@Slf4j
public class EurekaStateListener
{

    @EventListener(condition = "#event.replication==false")
    public void listen(EurekaInstanceCanceledEvent event)
    {
        String msg="您的服务"+event.getAppName()+"\n"+event.getServerId()+"已下线";
        log.info(msg);
    }

    @EventListener(condition = "#event.replication==false")
    public void listen(EurekaInstanceRegisteredEvent event) {
        InstanceInfo instanceInfo = event.getInstanceInfo();
        String msg="服务"+instanceInfo.getAppName()+"\n"+  instanceInfo.getHostName()+":"+ instanceInfo.getPort()+ " \nip: " +instanceInfo.getIPAddr() +"进行注册";
        log.info(msg);
    }

    @EventListener
    public void listen(EurekaInstanceRenewedEvent event) {
        log.info("服务{}进行续约", event.getServerId() +"  "+ event.getAppName());
    }

    @EventListener
    public void listen(EurekaRegistryAvailableEvent event) {
        log.info("注册中心启动,{}", System.currentTimeMillis());
    }

    @EventListener
    public void listen(EurekaServerStartedEvent event) {
        log.info("注册中心服务端启动,{}", System.currentTimeMillis());
    }

}