dubbo 初始化流程

FailbackRegistry

ref = createProxy(map)

RegistryDirectory

DubboNamespaceHandler

registry.subscribe

ZookeeperRegistry

doSubscribe

创建protocol代理对象

refer

notify通知节点变化

消费者

subscribe

doRefer

RegistryProtocol

ReferenceConfig

init

registerBeanDefinitionParser(\"reference\

init方法解析xml中的标签