spring源码学习笔记-初始化(三) registerBeanPostProcessors

refresh 方法如下:


// Register bean processors that intercept bean creation.
registerBeanPostProcessors(beanFactory);



	String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);

		// 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.
		int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
		beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));

		// Separate between BeanPostProcessors that implement PriorityOrdered,
		// Ordered, and the rest.
		List priorityOrderedPostProcessors = new ArrayList();
		List internalPostProcessors = new ArrayList();
		List orderedPostProcessorNames = new ArrayList();
		List nonOrderedPostProcessorNames = new ArrayList();
		for (String ppName : postProcessorNames) {
			if (isTypeMatch(ppName, PriorityOrdered.class)) {
				BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
				priorityOrderedPostProcessors.add(pp);
				if (pp instanceof MergedBeanDefinitionPostProcessor) {
					internalPostProcessors.add(pp);
				}
			}
			else if (isTypeMatch(ppName, Ordered.class)) {
				orderedPostProcessorNames.add(ppName);
			}
			else {
				nonOrderedPostProcessorNames.add(ppName);
			}
		}

		// First, register the BeanPostProcessors that implement PriorityOrdered.
		OrderComparator.sort(priorityOrderedPostProcessors);
		registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);

		// Next, register the BeanPostProcessors that implement Ordered.
		List orderedPostProcessors = new ArrayList();
		for (String ppName : orderedPostProcessorNames) {
			BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
			orderedPostProcessors.add(pp);
			if (pp instanceof MergedBeanDefinitionPostProcessor) {
				internalPostProcessors.add(pp);
			}
		}
		OrderComparator.sort(orderedPostProcessors);
		registerBeanPostProcessors(beanFactory, orderedPostProcessors);

		// Now, register all regular BeanPostProcessors.
		List nonOrderedPostProcessors = new ArrayList();
		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.
		OrderComparator.sort(internalPostProcessors);
		registerBeanPostProcessors(beanFactory, internalPostProcessors);

		beanFactory.addBeanPostProcessor(new ApplicationListenerDetector());

分析:

第1行代码通过传递过来的beanfactory查找类型为BeanPostProcessor的bean的名字;

第6行代码获得类型为BeanPostProcessor的bean数量+1+类型为beanPostProcessor的bean的长度; (+1表示下面beanProcessorChecker)

第7行代码为beanFactory注册一个BeanPostPossorChecker类,这个类的作用当一个bean没有被所有的beanPostProcessor处理后打印一行info日志。

第11行代码开始主要是区别对待继承ProiorityOrdered接口,排序并且设置;这里声明一个BeanPostProcesor的ArrayList;

第12行代码声明一个存放内部的BeanPostProcessor的List;

第13行代码声明一个存放排序BeanPostProcessor的Name的List;

第14行代码声明一个存放非排序的BeanPostProcessor的name的List;

第15行代码开始的for循环,循环BeanPostProcessor的Name,如果是匹配PriorityOrdered接口,进入if,否则如果是实习Ordered接口

执行else  if,





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