9.Java Spring框架源码分析-IOC-注册BeanPostProcessor

目录

1. 要研究的代码

  • AbstractApplicationContext registerBeanPostProcessors
protected void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory) {
	//传入当前bean工厂,注册BeanPostProcessor并调用postProcess方法
	PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this);
}

PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this);这个作用时传入当前bean工厂,注册BeanPostProcessor并调用postProcess方法

  • registerBeanPostProcessors（PostProcessorRegistrationDelegate）
public static void registerBeanPostProcessors(
		ConfigurableListableBeanFactory beanFactory, AbstractApplicationContext applicationContext) {

	//从bean工厂中获取类型为BeanPostProcessor的PostProcssor
	String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);

	// Register BeanPostProcessorChecker that logs an info message when
	// a bean is  
	// a bean is not eligible for getting processed by all BeanPostProcessors.
	int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
	beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));

	// Separate between BeanPostProcessors that implement PriorityOrdered,
	// Ordered, and the rest.
	List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
	List<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>();
	List<String> orderedPostProcessorNames = new ArrayList<String>();
	List<String> nonOrderedPostProcessorNames = new ArrayList<String>();
	//遍历所有PostProcessor，分为PriorityOrdered、MergedBeanDefinitionPostProcessor、Ordered、普通的四类
	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.
	//排序、把实现了PriorityOrdered的BeanPostProcessor加入到bean工厂里
	sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
	registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);

	// Next, register the BeanPostProcessors that implement Ordered.
	//排序、把实现了Ordered的BeanPostProcessor加入到bean工厂里
	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(orderedPostProcessors, beanFactory);
	registerBeanPostProcessors(beanFactory, orderedPostProcessors);

	// Now, register all regular BeanPostProcessors.
	//排序、把普通的BeanPostProcessor加入到bean工厂里
	List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
	for (String ppName : nonOrderedPostProcessorNames) {
		BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
		nonOrderedPostProcessors.add(pp);
		if (pp instanceof MergedBeanDefinitionPostProcessor) {
			internalPostProcessors.add(pp);
		}
	}
	registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);

	// Finally, re-register all internal BeanPostProcessors.
	////排序、把MergedBeanDefinitionPostProcessor类型的BeanPostProcessor加入到bean工厂里
	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).
	//最后加入一个ApplicationListenerDetector
	beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));
}

2. 获取所有类型为BeanPostProcessor的PostProcessor

//从bean工厂中获取类型为BeanPostProcessor的PostProcssor
String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);

3. 遍历分成PriorityOrdered、MergedBeanDefinitionPostProcessor、Ordered、普通的四类

List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
List<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>();
List<String> orderedPostProcessorNames = new ArrayList<String>();
List<String> nonOrderedPostProcessorNames = new ArrayList<String>();
//遍历所有PostProcessor，分为PriorityOrdered、MergedBeanDefinitionPostProcessor、Ordered、普通的四类
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);
    }
}

4. 排序、把实现了PriorityOrdered的BeanPostProcessor加入到bean工厂里

// First, register the BeanPostProcessors that implement PriorityOrdered.
//排序、把实现了PriorityOrdered的BeanPostProcessor加入到bean工厂里
sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);

5. 排序、把实现了Ordered的BeanPostProcessor加入到bean工厂里

// Next, register the BeanPostProcessors that implement Ordered.
//排序、把实现了Ordered的BeanPostProcessor加入到bean工厂里
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(orderedPostProcessors, beanFactory);
registerBeanPostProcessors(beanFactory, orderedPostProcessors);

6. 排序、把普通的BeanPostProcessor加入到bean工厂里

// Now, register all regular BeanPostProcessors.
//排序、把普通的BeanPostProcessor加入到bean工厂里
List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
for (String ppName : nonOrderedPostProcessorNames) {
    BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
    nonOrderedPostProcessors.add(pp);
    if (pp instanceof MergedBeanDefinitionPostProcessor) {
        internalPostProcessors.add(pp);
    }
}
registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);

7. 排序、把MergedBeanDefinitionPostProcessor类型的BeanPostProcessor加入到bean工厂里

// Finally, re-register all internal BeanPostProcessors.
////排序、把MergedBeanDefinitionPostProcessor类型的BeanPostProcessor加入到bean工厂里
sortPostProcessors(internalPostProcessors, beanFactory);
registerBeanPostProcessors(beanFactory, internalPostProcessors);
posted @ 2025-07-04 19:03  ThinkerQAQ  阅读(18)  评论(0)    收藏  举报