聊聊NacosDiscoveryEndpointsAutoConfiguration
- 2019 年 10 月 7 日
- 筆記
序
本文主要研究一下NacosDiscoveryEndpointsAutoConfiguration
NacosDiscoveryEndpointsAutoConfiguration
nacos-spring-boot-project/nacos-discovery-spring-boot-actuator/src/main/java/com/alibaba/boot/nacos/discovery/actuate/autoconfigure/NacosDiscoveryEndpointsAutoConfiguration.java
@Configuration public class NacosDiscoveryEndpointsAutoConfiguration { @Bean @ConditionalOnMissingBean @ConditionalOnEnabledEndpoint public NacosDiscoveryEndpoint nacosDiscoveryEndpoint() { return new NacosDiscoveryEndpoint(); } }
- NacosDiscoveryEndpointsAutoConfiguration注册了NacosDiscoveryEndpoint
NacosDiscoveryEndpoint
nacos-spring-boot-project/nacos-discovery-spring-boot-actuator/src/main/java/com/alibaba/boot/nacos/discovery/actuate/endpoint/NacosDiscoveryEndpoint.java
@Endpoint(id = NacosDiscoveryConstants.ENDPOINT_PREFIX) public class NacosDiscoveryEndpoint { @Autowired private ApplicationContext applicationContext; private static final Integer PAGE_SIZE = 100; @ReadOperation public Map<String, Object> invoke() { Map<String, Object> result = new HashMap<>(); result.put("nacosDiscoveryGlobalProperties", PropertiesUtils.extractSafeProperties(applicationContext.getBean( DISCOVERY_GLOBAL_NACOS_PROPERTIES_BEAN_NAME, Properties.class))); NacosServiceFactory nacosServiceFactory = CacheableEventPublishingNacosServiceFactory.getSingleton(); JSONArray array = new JSONArray(); for (NamingService namingService : nacosServiceFactory.getNamingServices()) { JSONObject jsonObject = new JSONObject(); try { jsonObject.put("servicesOfServer", namingService.getServicesOfServer(0, PAGE_SIZE)); jsonObject.put("subscribeServices", namingService.getSubscribeServices()); array.add(jsonObject); } catch (Exception e) { jsonObject.put("serverStatus", namingService.getServerStatus() + ": " + NacosUtils.SEPARATOR + e.getMessage()); } } result.put("namingServersStatus", array); return result; } }
- NacosDiscoveryEndpoint提供了一个ReadOperation，它返回的map里头会有nacosDiscoveryGlobalProperties及namingServersStatus；namingServersStatus是个JSONArray，每个JSONArray的元素是个JSONObject，JSONObject有servicesOfServer、subscribeServices；其中servicesOfServer通过namingService.getServicesOfServer(0, PAGE_SIZE)获取，PAGE_SIZE为100
NacosDiscoveryBeanDefinitionRegistrar
nacos-spring-context-0.3.3-sources.jar!/com/alibaba/nacos/spring/context/annotation/discovery/NacosDiscoveryBeanDefinitionRegistrar.java
public class NacosDiscoveryBeanDefinitionRegistrar implements ImportBeanDefinitionRegistrar, EnvironmentAware { private Environment environment; @Override public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) { AnnotationAttributes attributes = AnnotationAttributes.fromMap( importingClassMetadata.getAnnotationAttributes(EnableNacosDiscovery.class.getName())); // Register Global Nacos Properties Bean registerGlobalNacosProperties(attributes, registry, environment, DISCOVERY_GLOBAL_NACOS_PROPERTIES_BEAN_NAME); // Register Nacos Common Beans registerNacosCommonBeans(registry); // Register Nacos Discovery Beans registerNacosDiscoveryBeans(registry); } @Override public void setEnvironment(Environment environment) { this.environment = environment; } }
- NacosDiscoveryBeanDefinitionRegistrar实现了ImportBeanDefinitionRegistrar, EnvironmentAware接口，其registerBeanDefinitions从importingClassMetadata获取EnableNacosDiscovery的attributes，然后通过registerGlobalNacosProperties方法注册DISCOVERY_GLOBAL_NACOS_PROPERTIES_BEAN_NAME
NacosBeanUtils
nacos-spring-context-0.3.3-sources.jar!/com/alibaba/nacos/spring/util/NacosBeanUtils.java
public abstract class NacosBeanUtils { //...... public static void registerGlobalNacosProperties(AnnotationAttributes attributes, BeanDefinitionRegistry registry, PropertyResolver propertyResolver, String beanName) { if (attributes == null) { return; // Compatible with null } AnnotationAttributes globalPropertiesAttributes = attributes.getAnnotation("globalProperties"); registerGlobalNacosProperties((Map<?, ?>) globalPropertiesAttributes, registry, propertyResolver, beanName); } public static void registerGlobalNacosProperties(Map<?, ?> globalPropertiesAttributes, BeanDefinitionRegistry registry, PropertyResolver propertyResolver, String beanName) { Properties globalProperties = resolveProperties(globalPropertiesAttributes, propertyResolver); registerSingleton(registry, beanName, globalProperties); } public static void registerSingleton(BeanDefinitionRegistry registry, String beanName, Object singletonObject) { SingletonBeanRegistry beanRegistry = null; if (registry instanceof SingletonBeanRegistry) { beanRegistry = (SingletonBeanRegistry) registry; } else if (registry instanceof AbstractApplicationContext) { // Maybe AbstractApplicationContext or its sub-classes beanRegistry = ((AbstractApplicationContext) registry).getBeanFactory(); } // Register Singleton Object if possible if (beanRegistry != null) { // Determine in advance whether injected with beans if (!beanRegistry.containsSingleton(beanName)) { beanRegistry.registerSingleton(beanName, singletonObject); } } } //...... }
- NacosBeanUtils的registerGlobalNacosProperties方法从AnnotationAttributes获取globalProperties的AnnotationAttributes，然后通过registerGlobalNacosProperties解析AnnotationAttributes的属性，最后registerSingleton
小结
NacosDiscoveryEndpointsAutoConfiguration注册了NacosDiscoveryEndpoint；NacosDiscoveryEndpoint提供了一个ReadOperation，它返回的map里头会有nacosDiscoveryGlobalProperties及namingServersStatus；namingServersStatus是个JSONArray，每个JSONArray的元素是个JSONObject，JSONObject有servicesOfServer、subscribeServices；其中servicesOfServer通过namingService.getServicesOfServer(0, PAGE_SIZE)获取，PAGE_SIZE为100
