Dubbo源码解析

Dubbo学习；

Dubbo发布注册订阅的口子： @Service-bean实例化过程 ServiceAnnotationBeanPostProcessor-处理器，解析ServiceBean，并把Bean定义注册到spring容器     postProcessBeanDefinitionRegistry方法         registerServiceBeans方法     //调用下面的方法构造ServiceBean-BeanDefinition     AbstractBeanDefinition buildServiceBeanDefinition(Service service, Class<?> interfaceClass,String annotatedServiceBeanName)         BeanDefinitionBuilder builder = rootBeanDefinition(ServiceBean.class); ServiceBean里面有服务发布暴露的处理     //基于ContextRefreshedEvent和InitializingBean-afterPropertiesSet()两种处理时机     export(); @Reference-bean实例化过程 ReferenceAnnotationBeanPostProcessor-处理器，解析ReferenceBean     这里使用dubbo自己的注入解析     AnnotationInjectedBeanPostProcessor解析器，把Reference注解         getInjectedObject(A annotation, Object bean, String beanName, Class<?> injectedType,InjectionMetadata.InjectedElement injectedElement)方法         //返回ReferenceBean动态代理对象，ReferenceBean是个FactoryBean，在bean实例化，getBean的时候会调用ReferenceConfig.get()方法，订阅provider实例         Object proxy = buildProxy(referencedBeanName, referenceBean, injectedType);         //如果注入bean本身为Service-bean,则提前，基于ServiceBeanExportedEvent订阅provider实例。启动         onServiceBeanExportEvent((ServiceBeanExportedEvent) event);

****************************************************************************************************************************** 1、@Servie、@Reference注解元数据收集 org.apache.dubbo.metadata.annotation.processing.ServiceDefinitionMetadataAnnotationProcessor     boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv)->装换为：List<ServiceDefinition> serviceDefinitions 2、元数据注册： org.apache.dubbo.metadata.report.support.AbstractMetadataReport     服务提供者：void doStoreProviderMetadata(MetadataIdentifier providerMetadataIdentifier, String serviceDefinitions);     服务消费者void doStoreConsumerMetadata(MetadataIdentifier consumerMetadataIdentifier, String serviceParameterString);     保存：void doSaveMetadata(ServiceMetadataIdentifier metadataIdentifier, URL url);     删除：void doRemoveMetadata(ServiceMetadataIdentifier metadataIdentifier);     服务地址：List<String> doGetExportedURLs(ServiceMetadataIdentifier metadataIdentifier);     订阅数据：void doSaveSubscriberData(SubscriberMetadataIdentifier subscriberMetadataIdentifier, String urlListStr);     订阅地址：String doGetSubscribedURLs(SubscriberMetadataIdentifier subscriberMetadataIdentifier); 3、元数据向zookeeper注册 org.apache.dubbo.metadata.store.zookeeper.ZookeeperMetadataReport     缓存双方元数据：     void doStoreProviderMetadata(MetadataIdentifier providerMetadataIdentifier, String serviceDefinitions)     void doStoreConsumerMetadata(MetadataIdentifier consumerMetadataIdentifier, String value)     初始化属性;ZookeeperMetadataReport(URL url, ZookeeperTransporter zookeeperTransporter)     @Override     public String getServiceDefinition(MetadataIdentifier metadataIdentifier) {         return zkClient.getContent(getNodePath(metadataIdentifier));     }

    private void storeMetadata(MetadataIdentifier metadataIdentifier, String v) {         zkClient.create(getNodePath(metadataIdentifier), v, false);     }

    String getNodePath(BaseMetadataIdentifier metadataIdentifier) {         return toRootDir() + metadataIdentifier.getUniqueKey(KeyTypeEnum.PATH);     }     缓存注册地址：boolean saveExportedURLs(String serviceName, String exportedServicesRevision, String exportedURLsContent) 4、服务地址注册:

org.apache.dubbo.config.ServiceConfig<T>       void export() //暴露方法  构造serviceMateData对象，然后把bean转url,进行发布      //协议自适应org.apache.dubbo.registry.integration.RegistryProtocol              Exporter<T> export(final Invoker<T> originInvoker) //调用register的   register方法 地址注册-接口方法：org.apache.dubbo.registry.RegistryService     void register(URL url);     void unregister(URL url);     void subscribe(URL url, NotifyListener listener);     void unsubscribe(URL url, NotifyListener listener);     List<URL> lookup(URL url); 注册监听-接口方法：org.apache.dubbo.registry.RegistryServiceListener     void onRegister(URL url);     void onUnregister(URL url);     void onSubscribe(URL url);     void onUnsubscribe(URL url); 具体注册方法实现： org.apache.dubbo.registry.integration.RegistryProtocol     Exporter<T> export(final Invoker<T> originInvoker) throws RpcException         注册，订阅方法：org.apache.dubbo.registry.support.AbstractRegistry         public AbstractRegistry(URL url)，初始化缓存             loadProperties();             notify(url.getBackupUrls());//并触发缓存历史监听         注册订阅：protected void recover() throws Exception     重新注册：void reExport(final Invoker<T> originInvoker, URL newInvokerUrl)     Invoker<T> refer(Class<T> type, URL url)         直接生成：return proxyFactory.getInvoker((T) registry, type, url);         或者：Invoker<T> doRefer(Cluster cluster, Registry registry, Class<T> type, URL url)                  获取服务提供者：Invoker<T> invoker = cluster.join(directory);->调用相应Cluster实例,筛选Invoker      5、服务订阅，发现：

org.apache.dubbo.registry.client.ServiceDiscoveryFactory     根据注册地址获取远程服务：ServiceDiscovery getServiceDiscovery(URL registryURL);     org.apache.dubbo.registry.client.ServiceDiscovery         void initialize(URL registryURL) throws Exception;         void destroy() throws Exception;         void register(ServiceInstance serviceInstance) throws RuntimeException;         void update(ServiceInstance serviceInstance) throws RuntimeException;         void unregister(ServiceInstance serviceInstance) throws RuntimeException;         服务实例:List<ServiceInstance> getInstances(String serviceName) throws NullPointerException;         服务变更监听:void addServiceInstancesChangedListener(ServiceInstancesChangedListener listener);         转发服务变更事件:void dispatchServiceInstancesChangedEvent(String serviceName);

服务注册与发现： org.apache.dubbo.registry.client.ServiceDiscoveryRegistry     public ServiceDiscoveryRegistry(URL registryURL) {         this.serviceDiscovery = createServiceDiscovery(registryURL);//发现对象         this.serviceNameMapping = ServiceNameMapping.getDefaultExtension();//服务名         String metadataStorageType = getMetadataStorageType(registryURL);//注册服务元数据         this.writableMetadataService = WritableMetadataService.getExtension(metadataStorageType);//client远程服务代理对象         this.subscribedURLsSynthesizers = initSubscribedURLsSynthesizers();//订阅URL     }     服务注册:super.register(url);     订阅url:subscribeURLs(url, subscribedURLs, serviceName);     url变更Listener:registerServiceInstancesChangedListener(url, new ServiceInstancesChangedListener(serviceName) {});     获取注册服务实例列表:List<ServiceInstance> serviceInstances = serviceDiscovery.getInstances(serviceName); 使用zookeeper的服务发现： org.apache.dubbo.registry.zookeeper.ZookeeperServiceDiscovery implements ServiceDiscovery, EventListener<ServiceInstancesChangedEvent>

服务发现开始：

org.apache.dubbo.config.ReferenceConfig<T>      T get()  //获取Reference对象             ref = createProxy(map)  //动态创建         invoker = REF_PROTOCOL.refer(interfaceClass, urls.get(0));//协议自适应           invoker = CLUSTER.join(new StaticDirectory(url, invokers));//调用集群筛选 7、消费端，远程服务代理对象生成： org.apache.dubbo.registry.client.metadata.proxy.DefaultMetadataServiceProxyFactory     MetadataService createProxy(ServiceInstance serviceInstance)         // Simply rely on the first metadata url, as stated in MetadataServiceURLBuilder.         Invoker<MetadataService> invoker = protocol.refer(MetadataService.class, urls.get(0));         return proxyFactory.getProxy(invoker); 8、远程调用： consumer端： org.apache.dubbo.rpc.protocol.dubbo.DubboInvoker<T> extends AbstractInvoker<T>     远程调用：Result doInvoke(final Invocation invocation)                 调用ExchangeClient结果返回：currentClient.request(inv, timeout, executor).thenApply(obj -> (AppResponse) obj); provider端: org.apache.dubbo.registry.client.metadata.proxy.DefaultMetadataServiceProxyFactory     MetadataService createProxy(ServiceInstance serviceInstance)         // Simply rely on the first metadata url, as stated in MetadataServiceURLBuilder.         Invoker<MetadataService> invoker = protocol.refer(MetadataService.class, urls.get(0));         return proxyFactory.getProxy(invoker); 反射调用         result = method.invoke(result, r.getValue());