实现ribbon更新consul服务列表

要实现ribbon更新consul服务列表，可以使用spring cloud提供的一些组件和配置。以下是一些步骤：

1. 添加依赖

在pom.xml中添加以下依赖：

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-all</artifactId>
    <version>2.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
    <version>2.2.6.RELEASE</version>
</dependency>

2. 配置文件

在application.yml中添加以下配置：

spring:
  application:
    name: your-service-name
  cloud:
    consul:
      host: localhost
      port: 8500
      discovery:
        instance-id: ${spring.application.name}:${spring.application.instance_id:${random.value}}
        health-check-path: /actuator/health
        health-check-interval: 10s
        tags: version=1.0
    ribbon:
      listOfServers: localhost:8080,localhost:8081

其中，`your-service-name`是你的服务名，`localhost`和端口号是consul的地址和端口号，`listOfServers`是你的服务地址列表。

3. 启用ribbon

在启动类上添加`@EnableDiscoveryClient`和`@EnableFeignClients`注解，启用发现客户端和Feign客户端。

4. 动态更新consul服务列表

可以使用consul提供的服务发现API，获取最新的服务列表，并将其更新到ribbon的`listOfServers`中。以下是一个简单的实现：

@Autowired
private DiscoveryClient discoveryClient;

@Scheduled(fixedDelay = 5000)
public void updateServerList() {
    List<ServiceInstance> instances = discoveryClient.getInstances("your-service-name");
    List<String> servers = new ArrayList<>();
    for (ServiceInstance instance : instances) {
        servers.add(instance.getHost() + ":" + instance.getPort());
    }
    ServerList serverList = new StaticServerList<>(servers);
    RibbonProperties ribbonProperties = new RibbonProperties();
    ribbonProperties.setListOfServers(servers);
    IClientConfig config = new DefaultClientConfigImpl(ribbonProperties);
    ServerListUpdater serverListUpdater = new PollingServerListUpdater();
    serverListUpdater.start(config);
    ServerListFilter<Server> filter = new ZonePreferenceServerListFilter<>();
    ILoadBalancer loadBalancer = new ZoneAwareLoadBalancer<>(config);
    loadBalancer.setServerListFilter(filter);
    loadBalancer.setServerList(serverList);
    RibbonLoadBalancerContext context = new RibbonLoadBalancerContext(loadBalancer, null);
    RibbonLoadBalancerClient ribbonLoadBalancerClient = new RibbonLoadBalancerClient(context);
    LoadBalancerFeignClient feignClient = new LoadBalancerFeignClient(ribbonLoadBalancerClient, new Client.Default(null, null));
    Feign.builder().client(feignClient).build();
}

以上代码会定时更新consul服务列表，并使用ribbon的负载均衡算法，将请求分发到不同的服务实例中。