From 17552d20888009c716f8d49bd595583cb029f7c0 Mon Sep 17 00:00:00 2001 From: congshuo_cnki Date: Wed, 6 Jul 2022 17:33:02 +0800 Subject: [PATCH] refresh --- .../BeanDefinitionRegistryPostProcessor.java | 4 +++ .../beans/cstest/jvm/DemoOne.java | 16 +++++++++ .../support/AbstractApplicationContext.java | 2 +- .../PostProcessorRegistrationDelegate.java | 35 ++++++++++++++++++- 4 files changed, 55 insertions(+), 2 deletions(-) create mode 100644 spring-beans/src/test/java/org/springframework/beans/cstest/jvm/DemoOne.java diff --git a/spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionRegistryPostProcessor.java b/spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionRegistryPostProcessor.java index aa4a6e6..7f43e9a 100644 --- a/spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionRegistryPostProcessor.java +++ b/spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionRegistryPostProcessor.java @@ -40,6 +40,10 @@ public interface BeanDefinitionRegistryPostProcessor extends BeanFactoryPostProc * * @param registry the bean definition registry used by the application context * @throws org.springframework.beans.BeansException in case of errors + * + * 在标准初始化之后修改应用程序上下文的内部 bean 定义注册表。所有常规 bean 定义都将被加载， + * 但尚未实例化任何 bean。这允许在下一个后处理阶段开始之前添加更多的 bean 定义。 + * 参数：registry - 应用程序上下文使用的 bean 定义注册 */ void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException; diff --git a/spring-beans/src/test/java/org/springframework/beans/cstest/jvm/DemoOne.java b/spring-beans/src/test/java/org/springframework/beans/cstest/jvm/DemoOne.java new file mode 100644 index 0000000..8f9f9dc --- /dev/null +++ b/spring-beans/src/test/java/org/springframework/beans/cstest/jvm/DemoOne.java @@ -0,0 +1,16 @@ +package org.springframework.beans.cstest.jvm; + +public class DemoOne { + + public static void main(String[] args) { + String s = new String("1111"); + String intern = s.intern(); + System.out.println(intern); + + String ss = new String("1") + new String("1"); + String sss = "22"; + ss.intern(); + System.err.println(ss == sss); + + } +} diff --git a/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java b/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java index eacdff6..401eafa 100644 --- a/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java +++ b/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java @@ -198,7 +198,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader @Nullable private ConfigurableEnvironment environment; - /** BeanFactoryPostProcessors to apply on refresh. */ + /** BeanFactoryPostProcessors to apply on refresh. 在刷新是使用*/ private final List beanFactoryPostProcessors = new ArrayList<>(); /** System time in milliseconds when this context started. */ diff --git a/spring-context/src/main/java/org/springframework/context/support/PostProcessorRegistrationDelegate.java b/spring-context/src/main/java/org/springframework/context/support/PostProcessorRegistrationDelegate.java index 849c6a9..0b8ec66 100644 --- a/spring-context/src/main/java/org/springframework/context/support/PostProcessorRegistrationDelegate.java +++ b/spring-context/src/main/java/org/springframework/context/support/PostProcessorRegistrationDelegate.java @@ -80,17 +80,23 @@ final class PostProcessorRegistrationDelegate { // Invoke BeanDefinitionRegistryPostProcessors first, if any. Set processedBeans = new HashSet<>(); - + /** 对BeanDefinitionRegistry类型的处理*/ if (beanFactory instanceof BeanDefinitionRegistry registry) { List regularPostProcessors = new ArrayList<>(); + /** BeanDefinitionRegistryPostProcessor */ List registryProcessors = new ArrayList<>(); for (BeanFactoryPostProcessor postProcessor : beanFactoryPostProcessors) { if (postProcessor instanceof BeanDefinitionRegistryPostProcessor registryProcessor) { + /** + * 对于BeanDefinitionRegistryPostProcessor类型，在BeanFactoryPostProcessor的基础上还有 + * 自己定义的方法，需要先调用 + */ registryProcessor.postProcessBeanDefinitionRegistry(registry); registryProcessors.add(registryProcessor); } else { + /** 记录常规 BeanFactoryPostProcessor*/ regularPostProcessors.add(postProcessor); } } @@ -99,9 +105,17 @@ final class PostProcessorRegistrationDelegate { // uninitialized to let the bean factory post-processors apply to them! // Separate between BeanDefinitionRegistryPostProcessors that implement // PriorityOrdered, Ordered, and the rest. + /** + * 不要在此处初始化 FactoryBeans：我们需要让所有常规 bean 保持未初始化状态， + * 以便 bean 工厂后处理器应用到它们！将实现 PriorityOrdered、Ordered 和其余部分的 + * BeanDefinitionRegistryPostProcessor 分开。 + */ List currentRegistryProcessors = new ArrayList<>(); // First, invoke the BeanDefinitionRegistryPostProcessors that implement PriorityOrdered. + /** + * 首先，调用实现 PriorityOrdered 的 BeanDefinitionRegistryPostProcessor。 + */ String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false); for (String ppName : postProcessorNames) { @@ -226,14 +240,23 @@ final class PostProcessorRegistrationDelegate { // Register BeanPostProcessorChecker that logs an info message when // a bean is created during BeanPostProcessor instantiation, i.e. when // a bean is not eligible for getting processed by all BeanPostProcessors. + /** + * BeanPostProcessorChecker 是一个普通的信息打印，可能会有些情况， + * 当Spring的配置中的后处理器还没有被注册就已经开始了bean的初始化时 + * 便会打印出BeanPostProcessorChecker中设定的信息。 + */ int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length; beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount)); // Separate between BeanPostProcessors that implement PriorityOrdered, // Ordered, and the rest. + /** 调用priorityOrdered保证排序*/ List priorityOrderedPostProcessors = new ArrayList<>(); + /** MergedBeanDefinitionPostProcessor*/ List internalPostProcessors = new ArrayList<>(); + /** 使用Ordered 保证排序*/ List orderedPostProcessorNames = new ArrayList<>(); + /** 无序BeanPostProcessor*/ List nonOrderedPostProcessorNames = new ArrayList<>(); for (String ppName : postProcessorNames) { if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) { @@ -252,9 +275,11 @@ final class PostProcessorRegistrationDelegate { } // First, register the BeanPostProcessors that implement PriorityOrdered. + /** 第 1 步，注册实现 PriorityOrdered 的 BeanPostProcessor。*/ sortPostProcessors(priorityOrderedPostProcessors, beanFactory); registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors); + /** 第 2 步，注册所有实现Ordered的BeanPostProcessor*/ // Next, register the BeanPostProcessors that implement Ordered. List orderedPostProcessors = new ArrayList<>(orderedPostProcessorNames.size()); for (String ppName : orderedPostProcessorNames) { @@ -267,6 +292,7 @@ final class PostProcessorRegistrationDelegate { sortPostProcessors(orderedPostProcessors, beanFactory); registerBeanPostProcessors(beanFactory, orderedPostProcessors); + /** 第 3 步，注册所有无序的BeanPostProcessor*/ // Now, register all regular BeanPostProcessors. List nonOrderedPostProcessors = new ArrayList<>(nonOrderedPostProcessorNames.size()); for (String ppName : nonOrderedPostProcessorNames) { @@ -278,12 +304,19 @@ final class PostProcessorRegistrationDelegate { } registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors); + /** + * 第 4 步，注册所有MergedBeanDefinitionPostProcessor类型的BeanPostProcessor， + * 并非重复注册 + * + * 在beanFactory.addBeanPostProcessor中会先移出已存在的BeanPostProcessor + */ // Finally, re-register all internal BeanPostProcessors. sortPostProcessors(internalPostProcessors, beanFactory); registerBeanPostProcessors(beanFactory, internalPostProcessors); // Re-register post-processor for detecting inner beans as ApplicationListeners, // moving it to the end of the processor chain (for picking up proxies etc). + /** 添加 ApplicationListener探测器*/ beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext)); } -- GitLab