@[toc]
Pre
Bean的生成过程
org.springframework.beans.factory.config.BeanPostProcessor 介绍
public interface BeanPostProcessor {
@Nullable
default Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
return bean;
}
@Nullable
default 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BeanPostProcessors
List<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ApplicationListenerDetector
beanFactory.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);
}
}
@Override
public 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#getBean
org.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#getBean
org.springframework.beans.factory.support.AbstractBeanFactory#doGetBean
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#createBean
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#doCreateBeandoCreateBean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#getBean
org.springframework.beans.factory.support.AbstractBeanFactory#doGetBean
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#createBean
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#doCreateBean
org.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
@Override
public 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 {
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
log.info("beanName: {}-----> postProcessBeforeInitialization",beanName);
return BeanPostProcessor.super.postProcessBeforeInitialization(bean, beanName);
}
@Override
public 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;
