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

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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，