Dubbo使用Zookeeper作爲配置中心的動態配置原理

利用TreeNodeCache監聽/dubbo/config下的字節點的變化，TreeCacheListener的實現類爲org.apache.dubbo.remoting.zookeeper.curator.CuratorZookeeperClient.CuratorWatcherImpl,這個類中封裝了org.apache.dubbo.configcenter.support.zookeeper.CacheListener的實例，後續zk節點變化後通知到CacheListener,CacheListener中又存在ConfigurationListener的實例。流程爲CuratorWatcherImpl -> CacheListener -> ConfigurationListener (ConsumerConfigurationListener,ReferenceConfigurationListener,ProviderConfigurationListener,ServiceConfigurationListener),這樣就實現了配置的動態變化。