spring源碼學習筆記-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<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
		List<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>();
		List<String> orderedPostProcessorNames = new ArrayList<String>();
		List<String> nonOrderedPostProcessorNames = new ArrayList<String>();
		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<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);
			}
		}
		OrderComparator.sort(orderedPostProcessors);
		registerBeanPostProcessors(beanFactory, orderedPostProcessors);

		// Now, register all regular BeanPostProcessors.
		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.
		OrderComparator.sort(internalPostProcessors);
		registerBeanPostProcessors(beanFactory, internalPostProcessors);

		beanFactory.addBeanPostProcessor(new ApplicationListenerDetector());
           

分析：

第1行代碼通過傳遞過來的beanfactory查找類型為BeanPostProcessor的bean的名字；

第6行代碼獲得類型為BeanPostProcessor的bean數量+1+類型為beanPostProcessor的bean的長度； （+1表示下面beanProcessorChecker）

第7行代碼為beanFactory注冊一個BeanPostPossorChecker類，這個類的作用當一個bean沒有被所有的beanPostProcessor處理後列印一行info日志。

第11行代碼開始主要是差別對待繼承ProiorityOrdered接口，排序并且設定；這裡聲明一個BeanPostProcesor的ArrayList；

第12行代碼聲明一個存放内部的BeanPostProcessor的List；

第13行代碼聲明一個存放排序BeanPostProcessor的Name的List；

第14行代碼聲明一個存放非排序的BeanPostProcessor的name的List；

第15行代碼開始的for循環，循環BeanPostProcessor的Name，如果是比對PriorityOrdered接口，進入if，否則如果是實習Ordered接口

執行else  if，