文章目录
- Pre
- Bean的生成过程
- org.springframework.beans.factory.config.BeanPostProcessor 介绍
- ApplicationContext注册Bean PostProcessor源码解析
- AbstractApplicationContext#refresh
- AbstractApplicationContext#registerBeanPostProcessors
- PostProcessorRegistrationDelegate.registerBeanPostProcessors
- 回调BeanPostProcessors的时机源码解析
- 扩展示例
- 小结
Pre
Spring Boot - 扩展接口一览
Bean的生成过程
org.springframework.beans.factory.config.BeanPostProcessor 介绍
public interface BeanPostProcessor {@Nullabledefault Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {return bean;}@Nullabledefault Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {return bean;}}
如果BeanPostProcessors接囗的实现类被注册到ioc容器,那么该容器的每个Bean在调用初始化方法之前,都会获得该接口实现类的一个回调。
要使用BeanPostProcessord回调,就必须先在容器中注册实现该接口的类,那么如何注册呢?
-
若使用
BeanFactory,则必须要显示的调用其addBeanPostProcessor方法进行注册,参数为BeanPostProcessor现类的实例; -
使用
ApplicationContext,那么容器会在配置文件在中自动寻找实现了BeanPostProcessor口的Bean,然后自动注册,我们只需要配置个BeanPostProcessor现类的Bean可以了。 -
多个的
BeanPostProcessorg实现类,只要实现Ordered接口,设置order属性就可以很轻确定不同实现类的处理顺序了; -
接口中的两个方法都要将传入的bean回,不能返回null,如果返回的是nu么我们通过
getBean将得不到目标
ApplicationContext注册Bean PostProcessor源码解析
AbstractApplicationContext#refresh
org.springframework.context.support.AbstractApplicationContext#refresh
来看下关键代码
public void refresh() throws BeansException, IllegalStateException {........// Register bean processors that intercept bean creation.registerBeanPostProcessors(beanFactory);........// Instantiate all remaining (non-lazy-init) singletons.// 实例化剩余的所有非延迟加载单例对象// 在上面的registerBeanPostProcessors中已经把所有BeanPostProcessors所有对象都已经实例化过了// 这加载的时候会判断bean是不是 FactoryBean类型的// 如果是FactoryBean类型，则getBean(&beanName),这里是把FactoryBean本身的对象给实例化了，而没有调它的getObject方法；// 还要判断是不是SmartFactoryBean类型的，SmartFactoryBean继承了FactoryBean接口；但是它多了一个 boolean isEagerInit();方法；这个方法就是判断是否需要通过FactoryBean的getObject()生成实例；// 如果不是FactoryBean类型，直接getBean就行了；// 还要判断是不是SmartInitializingSingleton接口，这个接口有个afterSingletonsInstantiated方法；// 循环所以bean判断是不是这个类型的，只要是这个类型就调用afterSingletonsInstantiated方法；finishBeanFactoryInitialization(beanFactory);........ }AbstractApplicationContext#registerBeanPostProcessors
先看 registerBeanPostProcessors
/*** Instantiate and register all BeanPostProcessor beans,* respecting explicit order if given.* <p>Must be called before any instantiation of application beans.*/protected void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory) {PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this);}
PostProcessorRegistrationDelegate.registerBeanPostProcessors
public static void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory, AbstractApplicationContext applicationContext) {/*** 代码走到了这里的时候其实 BeanDefinition数据已经被加载了，只是bean还没有被实例化所以这个是去容器里面找到所有类型为BeanPostProcessor的beanName*/String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));// 优先级最高的BeanPostProcessors，这类最先调用；需要实现PriorityOrdered接口List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>();//内部BeanPostProcessorsList<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>();//继承了Ordered接口，优先级比上面低一点List<String> orderedPostProcessorNames = new ArrayList<String>();//这就是普通的了，优先级最低List<String> nonOrderedPostProcessorNames = new ArrayList<String>();//下面的这些代码就是遍历所有postProcessorNames，按优先级排序；类型PriorityOrdered>Ordered>普通；在这个类型基础上，还要对他们的order属性就行排序；for (String ppName : postProcessorNames) {if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);priorityOrderedPostProcessors.add(pp);if (pp instanceof MergedBeanDefinitionPostProcessor) {internalPostProcessors.add(pp);}}else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {orderedPostProcessorNames.add(ppName);}else {nonOrderedPostProcessorNames.add(ppName);}}// First, register the BeanPostProcessors that implement PriorityOrdered.sortPostProcessors(beanFactory, priorityOrderedPostProcessors);registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);// Next, register the BeanPostProcessors that implement Ordered.List<BeanPostProcessor> orderedPostProcessors = new ArrayList<BeanPostProcessor>();for (String ppName : orderedPostProcessorNames) {BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);orderedPostProcessors.add(pp);if (pp instanceof MergedBeanDefinitionPostProcessor) {internalPostProcessors.add(pp);}}sortPostProcessors(beanFactory, orderedPostProcessors);registerBeanPostProcessors(beanFactory, orderedPostProcessors);// Now, register all regular BeanPostProcessors.List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanPostProcessor>();for (String ppName : nonOrderedPostProcessorNames) {//这里要注意一下了，看到没有，这个时候已经调用了getBean来生成实例对象了；BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);nonOrderedPostProcessors.add(pp);if (pp instanceof MergedBeanDefinitionPostProcessor) {internalPostProcessors.add(pp);}}registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);// 排序sortPostProcessors(beanFactory, internalPostProcessors);//注册registerBeanPostProcessors(beanFactory, internalPostProcessors);// 加入ApplicationListenerDetectorbeanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));}/*** 注册 BeanPostProcessor beans.* 容器中beanPostProcessors是一个ArrayList来持有这些BeanPostProcessors*/private static void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory, List<BeanPostProcessor> postProcessors) {for (BeanPostProcessor postProcessor : postProcessors) {beanFactory.addBeanPostProcessor(postProcessor);}}
@Overridepublic void addBeanPostProcessor(BeanPostProcessor beanPostProcessor) {Assert.notNull(beanPostProcessor, "BeanPostProcessor must not be null");this.beanPostProcessors.remove(beanPostProcessor);this.beanPostProcessors.add(beanPostProcessor);//将是否 hasInstantiationAwareBeanPostProcessors设置为true if (beanPostProcessor instanceof InstantiationAwareBeanPostProcessor) {this.hasInstantiationAwareBeanPostProcessors = true;}if (beanPostProcessor instanceof DestructionAwareBeanPostProcessor) {this.hasDestructionAwareBeanPostProcessors = true;}}回调BeanPostProcessors的时机源码解析
org.springframework.context.support.PostProcessorRegistrationDelegate#registerBeanPostProcessors()BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);org.springframework.beans.factory.support.AbstractBeanFactory#getBeanorg.springframework.beans.factory.support.AbstractBeanFactory#doGetBean
doGetBean 重点看
// Create bean instance.
if (mbd.isSingleton()) {sharedInstance = getSingleton(beanName, () -> {try {return createBean(beanName, mbd, args);}catch (BeansException ex) {// Explicitly remove instance from singleton cache: It might have been put there// eagerly by the creation process, to allow for circular reference resolution.// Also remove any beans that received a temporary reference to the bean.destroySingleton(beanName);throw ex;}});beanInstance = getObjectForBeanInstance(sharedInstance, name, beanName, mbd);
}
继续看 createBean
org.springframework.context.support.PostProcessorRegistrationDelegate#registerBeanPostProcessors()BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);org.springframework.beans.factory.support.AbstractBeanFactory#getBeanorg.springframework.beans.factory.support.AbstractBeanFactory#doGetBean org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#createBeanorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#doCreateBean
doCreateBean重点看
// Initialize the bean instance.
Object exposedObject = bean;
try {// 属性设置populateBean(beanName, mbd, instanceWrapper);// BeanPostProcessors两个方法都在这里面exposedObject = initializeBean(beanName, exposedObject, mbd);
}
org.springframework.context.support.PostProcessorRegistrationDelegate#registerBeanPostProcessors()BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);org.springframework.beans.factory.support.AbstractBeanFactory#getBeanorg.springframework.beans.factory.support.AbstractBeanFactory#doGetBean org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#createBeanorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#doCreateBeanorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#initializeBean
继续核心 initializeBean
protected Object initializeBean(String beanName, Object bean, @Nullable RootBeanDefinition mbd) {if (System.getSecurityManager() != null) {AccessController.doPrivileged((PrivilegedAction<Object>) () -> {invokeAwareMethods(beanName, bean);return null;}, getAccessControlContext());}else {// 检查Aware相关接口并设置相关依赖invokeAwareMethods(beanName, bean);}Object wrappedBean = bean;if (mbd == null || !mbd.isSynthetic()) {// BeanPostProcessor前置处理wrappedBean = applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);}try {// 检查是否是InitializingBean以决定是否调用afterPropertiesSet方法 // 检查是否配置有自定义的init-method方法invokeInitMethods(beanName, wrappedBean, mbd);}catch (Throwable ex) {throw new BeanCreationException((mbd != null ? mbd.getResourceDescription() : null),beanName, "Invocation of init method failed", ex);}if (mbd == null || !mbd.isSynthetic()) {// BeanPostProcessor后置处理wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);}return wrappedBean;}
看下 applyBeanPostProcessorsAfterInitialization
//注意 每一个实例对象触发这个的时候 都是执行所有的BeanPostProcessors实例对象@Overridepublic Object applyBeanPostProcessorsAfterInitialization(Object existingBean, String beanName)throws BeansException {Object result = existingBean;for (BeanPostProcessor processor : getBeanPostProcessors()) {Object current = processor.postProcessAfterInitialization(result, beanName);//这里是循环// result =BeanPostProcessor调用执行方法；返回的对象还是result，只是有可能被某个BeanPostProcessor加强了 beanProcessor.postProcessAfterInitialization(result, beanName);if (current == null) {return result;}result = current;}return result;}
扩展示例
package com.artisan.bootspringextend.testextends;import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.annotation.Configuration;/*** @author 小工匠* @version 1.0* @description: TODO* @date 2022/11/27 21:22* @mark: show me the code , change the world*/@Slf4j
@Configuration
public class ExtendBeanPostProcessor implements BeanPostProcessor {@Overridepublic Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {log.info("beanName: {}-----> postProcessBeforeInitialization",beanName);return BeanPostProcessor.super.postProcessBeforeInitialization(bean, beanName);}@Overridepublic Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {log.info( "beanName: {} ------> postProcessAfterInitialization",beanName);return BeanPostProcessor.super.postProcessAfterInitialization(bean, beanName);}}看日志
2022-11-27 22:07:40.269 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: bootSpringExtendApplication-----> postProcessBeforeInitialization
2022-11-27 22:07:40.271 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: bootSpringExtendApplication ------> postProcessAfterInitialization
2022-11-27 22:07:40.271 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.AutoConfigurationPackages-----> postProcessBeforeInitialization
2022-11-27 22:07:40.272 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.AutoConfigurationPackages ------> postProcessAfterInitialization
2022-11-27 22:07:40.273 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.273 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.281 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.281 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.284 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: objectNamingStrategy-----> postProcessBeforeInitialization
2022-11-27 22:07:40.284 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: objectNamingStrategy ------> postProcessAfterInitialization
2022-11-27 22:07:40.294 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: mbeanServer-----> postProcessBeforeInitialization
2022-11-27 22:07:40.294 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: mbeanServer ------> postProcessAfterInitialization
2022-11-27 22:07:40.297 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: mbeanExporter-----> postProcessBeforeInitialization
2022-11-27 22:07:40.297 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: mbeanExporter ------> postProcessAfterInitialization
2022-11-27 22:07:40.299 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.299 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.303 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: springApplicationAdminRegistrar-----> postProcessBeforeInitialization
2022-11-27 22:07:40.304 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: springApplicationAdminRegistrar ------> postProcessAfterInitialization
2022-11-27 22:07:40.307 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.aop.AopAutoConfiguration$ClassProxyingConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.307 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.aop.AopAutoConfiguration$ClassProxyingConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.308 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.aop.AopAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.308 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.aop.AopAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.308 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.availability.ApplicationAvailabilityAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.308 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.availability.ApplicationAvailabilityAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.310 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: applicationAvailability-----> postProcessBeforeInitialization
2022-11-27 22:07:40.310 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: applicationAvailability ------> postProcessAfterInitialization
2022-11-27 22:07:40.311 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.311 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.311 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.context.properties.BoundConfigurationProperties-----> postProcessBeforeInitialization
2022-11-27 22:07:40.311 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.context.properties.BoundConfigurationProperties ------> postProcessAfterInitialization
2022-11-27 22:07:40.312 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.context.properties.EnableConfigurationPropertiesRegistrar.methodValidationExcludeFilter-----> postProcessBeforeInitialization
2022-11-27 22:07:40.312 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.context.properties.EnableConfigurationPropertiesRegistrar.methodValidationExcludeFilter ------> postProcessAfterInitialization
2022-11-27 22:07:40.313 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.context.LifecycleAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.313 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.context.LifecycleAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.329 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: spring.lifecycle-org.springframework.boot.autoconfigure.context.LifecycleProperties-----> postProcessBeforeInitialization
2022-11-27 22:07:40.329 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: spring.lifecycle-org.springframework.boot.autoconfigure.context.LifecycleProperties ------> postProcessAfterInitialization
2022-11-27 22:07:40.330 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: lifecycleProcessor-----> postProcessBeforeInitialization
2022-11-27 22:07:40.330 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: lifecycleProcessor ------> postProcessAfterInitialization
2022-11-27 22:07:40.333 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: spring.info-org.springframework.boot.autoconfigure.info.ProjectInfoProperties-----> postProcessBeforeInitialization
2022-11-27 22:07:40.333 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: spring.info-org.springframework.boot.autoconfigure.info.ProjectInfoProperties ------> postProcessAfterInitialization
2022-11-27 22:07:40.334 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.334 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.334 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.334 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.336 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: spring.task.execution-org.springframework.boot.autoconfigure.task.TaskExecutionProperties-----> postProcessBeforeInitialization
2022-11-27 22:07:40.336 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: spring.task.execution-org.springframework.boot.autoconfigure.task.TaskExecutionProperties ------> postProcessAfterInitialization
2022-11-27 22:07:40.340 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: taskExecutorBuilder-----> postProcessBeforeInitialization
2022-11-27 22:07:40.340 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: taskExecutorBuilder ------> postProcessAfterInitialization
2022-11-27 22:07:40.341 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.task.TaskSchedulingAutoConfiguration-----> postProcessBeforeInitialization
2022-11-27 22:07:40.341 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: org.springframework.boot.autoconfigure.task.TaskSchedulingAutoConfiguration ------> postProcessAfterInitialization
2022-11-27 22:07:40.343 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: spring.task.scheduling-org.springframework.boot.autoconfigure.task.TaskSchedulingProperties-----> postProcessBeforeInitialization
2022-11-27 22:07:40.344 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: spring.task.scheduling-org.springframework.boot.autoconfigure.task.TaskSchedulingProperties ------> postProcessAfterInitialization
2022-11-27 22:07:40.345 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: taskSchedulerBuilder-----> postProcessBeforeInitialization
2022-11-27 22:07:40.345 INFO 12876 --- [ main] c.a.b.t.ExtendBeanPostProcessor : beanName: taskSchedulerBuilder ------> postProcessAfterInitialization
2022-11-27 22:07:40.362 INFO 12876 --- [ main] c.a.b.BootSpringExtendApplication : Started BootSpringExtendApplication in 0.822 seconds (JVM running for 2.124)Process finished with exit code 0
小结
总结一下：
BeanPostProcessors册发生在容器启动的时候;自动注册BeanPostProcessors类型;- 只要调用
getBean始化对象都会触发BeanPostProcessors口的两个方法,并且是所有BeanPostProcessors例都会触发; - 如果是
FactoryBean型,容器不会帮我们自动初始化它产生的实例
，除非是SmartFactoryBean实例,并且它的isEagerlnit()返回的是true; IOC器才会也帮我们调用它的getobject放法来生成实例;
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