Dubbo 启动加载流程、SPI流程

ReferenceAnnotationBeanPostProcessor

启动流程简化版：SpringBoot 启动Dubbo

loadResource

@EnableDubboConfig

ImportBeanDefinitionRegistrar

ApplicationListener<ServiceBeanExportedEvent>

启动流程：SpringBoot 启动Dubbo

ConfigurationBeanBindingsRegister

//解析配置文件，转换成AnnotationAttributes，注册到beanDefinitionMap

DynamicConfiguration

getDefaultExtension()

containsKey(name)

将配置解析class和注解解析class注册到beanDefinitionMap

getExtensionClasses()

publishEvent(new ContextRefreshedEvent(this));

DubboBootstrapApplicationListener

DubboComponentScanRegistrar

DubboBootstrap

initialize

先尝试从缓存加载，加载不到的话就调用文件系统读取SPI文件内容

AbstractApplicationContext

refresh()

ServiceAnnotationBeanPostProcessor

finishRefresh();

containsExtension(name)

启动时加载配置解析组件：配置解析，注解解析等

loadDirectory

Dubbo SPI：SPI的实现流程

Dubbo SPI：注册中心对SPI的调用

loadClass

BeanDefinitionRegistryPostProcessors

使用class全路径名获取SPI文件内容

DubboConfigConfigurationRegistrar

# 将配置解析相关的class注册到beanDefinitionMapDubboConfigConfiguration.Single.classDubboConfigConfiguration.Multiple.classReferenceAnnotationBeanPostProcessor.classConfigurationBeanBindingsRegister.class……

AbstractAnnotationBeanPostProcessor

处理@Reference 注解，Dubbo自己写了一套注入（inject）代码，将代理对象注入到Bean 属性

finishBeanFactoryInitialization(beanFactory);

ServiceClassPostProcessor

//解析DubboService 相关注解，将Bean注册到beanDefinitionMap

@DubboComponentScan

createBean

BeanDefinitionRegistryPostProcessor

invokeBeanFactoryPostProcessors(beanFactory);

populateBean

判断在SPI中能否取到name对应的类

getExtension(name)

useRegistryAsConfigCenterIfNecessary

# 将dubbo服务解析相关的class注册到beanDefinitionMapServiceAnnotationBeanPostProcessor.classReferenceAnnotationBeanPostProcessor.class……

ExtensionLoader

    public T getOrDefaultExtension(String name) { return containsExtension(name) ? getExtension(name) : getDefaultExtension(); }

@EnableDubbo

InstantiationAwareBeanPostProcessorAdapter

//@Reference 注解的后置处理器，目的是将RPC代理对象注入IOC 中

无法获取到

可以取到

createExtension

ConfigurationClassPostProcessor

使用解析器将解析的Bean注册到beanDefinitionMap

扩展点

startConfigCenter(){    ......    if (CollectionUtils.isNotEmpty(configCenters)) {            CompositeDynamicConfiguration compositeDynamicConfiguration = new CompositeDynamicConfiguration();            for (ConfigCenterConfig configCenter : configCenters) {                compositeDynamicConfiguration.addConfiguration(prepareEnvironment(configCenter));            }            environment.setDynamicConfiguration(compositeDynamicConfiguration);        }        configManager.refreshAll();}

loadExtensionClasses

反射调用类的实例并缓存起来

//导出Dubbo服务，用到了SPIexportServices();//对缓存的ReferenceConfig 进行处理referServices();

saveInExtensionClass

Dubbo启动类，这里主要是暴露服务（基于SPI），对缓存的referenceConfig 做最后的配置

DynamicConfigurationFactory

    static DynamicConfigurationFactory getDynamicConfigurationFactory(String name) { Class<DynamicConfigurationFactory> factoryClass = DynamicConfigurationFactory.class; ExtensionLoader<DynamicConfigurationFactory> loader = getExtensionLoader(factoryClass); return loader.getOrDefaultExtension(name); }