1.AbstractApplicationContext#refresh
invokeBeanFactoryPostProcessors(beanFactory);
2.AbstractApplicationContext#invokeBeanFactoryPostProcessors
protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) {
// GO
PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(beanFactory, getBeanFactoryPostProcessors());
// Detect a LoadTimeWeaver and prepare for weaving, if found in the meantime
// (e.g. through an @Bean method registered by ConfigurationClassPostProcessor)
if (!IN_NATIVE_IMAGE && beanFactory.getTempClassLoader() == null && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
}
}
3.PostProcessorRegistrationDelegate#invokeBeanFactoryPostProcessors
invokeBeanFactoryPostProcessors(registryProcessors, beanFactory);
4.PostProcessorRegistrationDelegate#invokeBeanFactoryPostProcessors
private static void invokeBeanFactoryPostProcessors(
Collection<? extends BeanFactoryPostProcessor> postProcessors, ConfigurableListableBeanFactory beanFactory) {
for (BeanFactoryPostProcessor postProcessor : postProcessors) {
StartupStep postProcessBeanFactory = beanFactory.getApplicationStartup().start("spring.context.bean-factory.post-process")
.tag("postProcessor", postProcessor::toString);
postProcessor.postProcessBeanFactory(beanFactory);
postProcessBeanFactory.end();
}
}
5.ConfigurationClassPostProcessor#postProcessBeanFactory
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
int factoryId = System.identityHashCode(beanFactory);
if (this.factoriesPostProcessed.contains(factoryId)) {
throw new IllegalStateException(
"postProcessBeanFactory already called on this post-processor against " + beanFactory);
}
this.factoriesPostProcessed.add(factoryId);
// 下面的if语句不会进入，因为在执行BeanFactoryPostProcessor时，会先执行BeanDefinitionRegistryPostProcessor
// 的postProcessorBeanDefinitionRegistry()方法
// 而在执行postProcessorBeanDefinitionRegistry方法时，都会调用processConfigBeanDefinitions方法，
// 这与postProcessorBeanFactory()方法的执行逻辑是一样的
// postProcessorBeanFactory()方法也会调用processConfigBeanDefinitions方法，为了避免重复执行，
// 所以在执行方法之前会先生成一个id，将id放入到一个set当中，每次执行之前
// 先判断id是否存在，所以在此处，永远不会进入到if语句中
if (!this.registriesPostProcessed.contains(factoryId)) {
// BeanDefinitionRegistryPostProcessor hook apparently not supported...
// Simply call processConfigurationClasses lazily at this point then.
// GO
processConfigBeanDefinitions((BeanDefinitionRegistry) beanFactory);
}
// 对加了@Configuration注解的配置类进行Cglib代理
// GO
enhanceConfigurationClasses(beanFactory);
// 添加一个BeanPostProcessor后置处理器
// Bean后置处理器最终会在Bean实例化和初始化的过程中执行，参与Bean的创建过程。
// 在上面已经通过源码分析了该后置处理器postProcessPropertyValues()方法，
// 其作用是为EnhanceConfiguration类的beanFactory属性赋值
// GO
beanFactory.addBeanPostProcessor(new ImportAwareBeanPostProcessor(beanFactory));
}
- processConfigBeanDefinition标记@Configuration类和非@Configuration类，并对所有候选配置类进行解析，其中标记配置类的方式是添加CONFIGURATION_CLASS_ATTRIBUTE属性,见ConfigurationClassUtils#checkConfigurationClassCandidate
Map<String, Object> config = metadata.getAnnotationAttributes(Configuration.class.getName());
if (config != null && !Boolean.FALSE.equals(config.get("proxyBeanMethods"))) {
beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_FULL);
}
else if (config != null || isConfigurationCandidate(metadata)) {
beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_LITE);
}
- enhanceConfigurationClasses对@Configuration类Cglib代理
6.ConfigurationClassPostProcessor#enhanceConfigurationClasses
public void enhanceConfigurationClasses(ConfigurableListableBeanFactory beanFactory) {
StartupStep enhanceConfigClasses = this.applicationStartup.start("spring.context.config-classes.enhance");
Map<String, AbstractBeanDefinition> configBeanDefs = new LinkedHashMap<>();
for (String beanName : beanFactory.getBeanDefinitionNames()) {
BeanDefinition beanDef = beanFactory.getBeanDefinition(beanName);
Object configClassAttr = beanDef.getAttribute(ConfigurationClassUtils.CONFIGURATION_CLASS_ATTRIBUTE);
MethodMetadata methodMetadata = null;
if (beanDef instanceof AnnotatedBeanDefinition) {
methodMetadata = ((AnnotatedBeanDefinition) beanDef).getFactoryMethodMetadata();
}
if ((configClassAttr != null || methodMetadata != null) && beanDef instanceof AbstractBeanDefinition) {
// Configuration class (full or lite) or a configuration-derived @Bean method
// -> resolve bean class at this point...
AbstractBeanDefinition abd = (AbstractBeanDefinition) beanDef;
if (!abd.hasBeanClass()) {
try {
abd.resolveBeanClass(this.beanClassLoader);
}
catch (Throwable ex) {
throw new IllegalStateException(
"Cannot load configuration class: " + beanDef.getBeanClassName(), ex);
}
}
}
if (ConfigurationClassUtils.CONFIGURATION_CLASS_FULL.equals(configClassAttr)) {
if (!(beanDef instanceof AbstractBeanDefinition)) {
throw new BeanDefinitionStoreException("Cannot enhance @Configuration bean definition '" +
beanName + "' since it is not stored in an AbstractBeanDefinition subclass");
}
else if (logger.isInfoEnabled() && beanFactory.containsSingleton(beanName)) {
logger.info("Cannot enhance @Configuration bean definition '" + beanName +
"' since its singleton instance has been created too early. The typical cause " +
"is a non-static @Bean method with a BeanDefinitionRegistryPostProcessor " +
"return type: Consider declaring such methods as 'static'.");
}
configBeanDefs.put(beanName, (AbstractBeanDefinition) beanDef);
}
}
if (configBeanDefs.isEmpty()) {
// nothing to enhance -> return immediately
enhanceConfigClasses.end();
return;
}
if (IN_NATIVE_IMAGE) {
throw new BeanDefinitionStoreException("@Configuration classes need to be marked as proxyBeanMethods=false. Found: " + configBeanDefs.keySet());
}
ConfigurationClassEnhancer enhancer = new ConfigurationClassEnhancer();
for (Map.Entry<String, AbstractBeanDefinition> entry : configBeanDefs.entrySet()) {
AbstractBeanDefinition beanDef = entry.getValue();
// If a @Configuration class gets proxied, always proxy the target class
beanDef.setAttribute(AutoProxyUtils.PRESERVE_TARGET_CLASS_ATTRIBUTE, Boolean.TRUE);
// Set enhanced subclass of the user-specified bean class
Class<?> configClass = beanDef.getBeanClass();
// 调用ConfigurationClassEnhancer.enhance()方法创建增强类
// GO
Class<?> enhancedClass = enhancer.enhance(configClass, this.beanClassLoader);
if (configClass != enhancedClass) {
if (logger.isTraceEnabled()) {
logger.trace(String.format("Replacing bean definition '%s' existing class '%s' with " +
"enhanced class '%s'", entry.getKey(), configClass.getName(), enhancedClass.getName()));
}
beanDef.setBeanClass(enhancedClass);
}
}
enhanceConfigClasses.tag("classCount", () -> String.valueOf(configBeanDefs.keySet().size())).end();
}
- 获取BeanDefinition中CONFIGURATION_CLASS_ATTRIBUTE属性
- 如果CONFIGURATION_CLASS_ATTRIBUTE不为空，加载类，若加载失败，抛异常
- CONFIGURATION_CLASS_ATTRIBUTE的值为CONFIGURATION_CLASS_FULL，那么是@Configuration注解类，并加入到configBeanDefs
- 创建增强类ConfigurationClassEnhancer，对@Configuration注解类增强
7.ConfigurationClassEnhancer#enhance
public Class<?> enhance(Class<?> configClass, @Nullable ClassLoader classLoader) {
if (EnhancedConfiguration.class.isAssignableFrom(configClass)) {
if (logger.isDebugEnabled()) {
logger.debug(String.format("Ignoring request to enhance %s as it has " +
"already been enhanced. This usually indicates that more than one " +
"ConfigurationClassPostProcessor has been registered (e.g. via " +
"<context:annotation-config>). This is harmless, but you may " +
"want check your configuration and remove one CCPP if possible",
configClass.getName()));
}
return configClass;
}
// 核心代码为 newEnHancer()
// GO
Class<?> enhancedClass = createClass(newEnhancer(configClass, classLoader));
if (logger.isTraceEnabled()) {
logger.trace(String.format("Successfully enhanced %s; enhanced class name is: %s",
configClass.getName(), enhancedClass.getName()));
}
return enhancedClass;
}
