spring中类型注解下的bean的加载顺序

基于java注解的方式配置的Appconfig中不同注解的bean的加载顺序：

　　注册的顺序： @ComponentScan > 实现ImportSelector  > 方法bean  >  @ImportResource("spring.xml") > 实现 ImportBeanDefinitionRegistrar  (相对的顺序，都在同一个配置类上配置)

详见spring源码  ConfigurationClassParser.java 的doProcessConfigurationClass（）方法：

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@Nullable     protected final SourceClass doProcessConfigurationClass(ConfigurationClass configClass, SourceClass sourceClass)             throws IOException {           if (configClass.getMetadata().isAnnotated(Component.class.getName())) {             // Recursively process any member (nested) classes first             processMemberClasses(configClass, sourceClass);         }           // Process any @PropertySource annotations         // 处理 @PropertySource    properties  key=value         for (AnnotationAttributes propertySource : AnnotationConfigUtils.attributesForRepeatable(                 sourceClass.getMetadata(), PropertySources.class,                 org.springframework.context.annotation.PropertySource.class)) {             if (this.environment instanceof ConfigurableEnvironment) {                 processPropertySource(propertySource);             }             else {                 logger.info("Ignoring @PropertySource annotation on [" + sourceClass.getMetadata().getClassName() +                         "]. Reason: Environment must implement ConfigurableEnvironment");             }         }           // Process any @ComponentScan annotations         //  处理@ComponentScan   将@Component修饰的bean注册到容器         Set<AnnotationAttributes> componentScans = AnnotationConfigUtils.attributesForRepeatable(                 sourceClass.getMetadata(), ComponentScans.class, ComponentScan.class);         if (!componentScans.isEmpty() &&                 !this.conditionEvaluator.shouldSkip(sourceClass.getMetadata(), ConfigurationPhase.REGISTER_BEAN)) {             for (AnnotationAttributes componentScan : componentScans) {                 // The config class is annotated with @ComponentScan -> perform the scan immediately                 // @ComponentScan扫描bean,返回@Component修饰的BeanDefinitionHolder 集合，并且                 // 会将bean注册到容器                 Set<BeanDefinitionHolder> scannedBeanDefinitions =                         this.componentScanParser.parse(componentScan, sourceClass.getMetadata().getClassName());                 // Check the set of scanned definitions for any further config classes and parse recursively if needed                 for (BeanDefinitionHolder holder : scannedBeanDefinitions) {                     BeanDefinition bdCand = holder.getBeanDefinition().getOriginatingBeanDefinition();                     if (bdCand == null) {                         bdCand = holder.getBeanDefinition();                     }                     if (ConfigurationClassUtils.checkConfigurationClassCandidate(bdCand, this.metadataReaderFactory)) {                         parse(bdCand.getBeanClassName(), holder.getBeanName());                     }                 }             }         }           // Process any @Import annotations         // 处理@Import   implements ImportSelector  并不会将bean注册到容器         processImports(configClass, sourceClass, getImports(sourceClass), true);           // Process any @ImportResource annotations         // 处理@ImportResource   bean不会注册到容器         AnnotationAttributes importResource =                 AnnotationConfigUtils.attributesFor(sourceClass.getMetadata(), ImportResource.class);         if (importResource != null) {             String[] resources = importResource.getStringArray("locations");             Class<? extends BeanDefinitionReader> readerClass = importResource.getClass("reader");             for (String resource : resources) {                 String resolvedResource = this.environment.resolveRequiredPlaceholders(resource);                 configClass.addImportedResource(resolvedResource, readerClass);             }         }           // Process individual @Bean methods         // 处理 bean method    bean不会注册到容器         Set<MethodMetadata> beanMethods = retrieveBeanMethodMetadata(sourceClass);         for (MethodMetadata methodMetadata : beanMethods) {             configClass.addBeanMethod(new BeanMethod(methodMetadata, configClass));         }           // Process default methods on interfaces         processInterfaces(configClass, sourceClass);           // Process superclass, if any         if (sourceClass.getMetadata().hasSuperClass()) {             String superclass = sourceClass.getMetadata().getSuperClassName();             if (superclass != null && !superclass.startsWith("java") &&                     !this.knownSuperclasses.containsKey(superclass)) {                 this.knownSuperclasses.put(superclass, configClass);                 // Superclass found, return its annotation metadata and recurse                 return sourceClass.getSuperClass();             }         }           // No superclass -> processing is complete         return null;     }