这部分处理的是 IOC 容器启动过程 4-postProcessBeanFactory () 中注册的扩展。接下来的操作就和上面很类似了。

阶段1- 查找所有的 Bean 并分类

  1. String[] postProcessorNames =
  2.                 beanFactory.getBeanNamesForType(BeanFactoryPostProcessor.class, true, false);
  4.         // Separate between BeanFactoryPostProcessors that implement PriorityOrdered,
  5.         // Ordered, and the rest.
  6.         List<BeanFactoryPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
  7.         List<String> orderedPostProcessorNames = new ArrayList<>();
  8.         List<String> nonOrderedPostProcessorNames = new ArrayList<>();
  9.         for (String ppName : postProcessorNames) {
  10.             if (processedBeans.contains(ppName)) {
  11.                 // skip - already processed in first phase above
  12.             } else if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
  13.                 priorityOrderedPostProcessors.add(beanFactory.getBean(ppName
  14.                                                                       , BeanFactoryPostProcessor.class));
  15.             } else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
  16.                 orderedPostProcessorNames.add(ppName);
  17.             } else {
  18.                 nonOrderedPostProcessorNames.add(ppName);
  19.             }
  20.         }

阶段2- 顺序执行有 PriorityOrdered的BeanFactoryPostProcessor

  1. // First, invoke the BeanFactoryPostProcessors that implement PriorityOrdered.
  2. sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
  3. invokeBeanFactoryPostProcessors(priorityOrderedPostProcessors, beanFactory);

阶段3- 顺序执行有 Ordered的BeanFactoryPostProcessor

  1. // Next, invoke the BeanFactoryPostProcessors that implement Ordered.
  2. List<BeanFactoryPostProcessor> orderedPostProcessors = new ArrayList<>(orderedPostProcessorNames.size());
  3. for (String postProcessorName : orderedPostProcessorNames) {
  4.     orderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
  5. }
  6. sortPostProcessors(orderedPostProcessors, beanFactory);
  7. invokeBeanFactoryPostProcessors(orderedPostProcessors, beanFactory);

阶段4- 顺序其他 BeanFactoryPostProcessor

  1. List<BeanFactoryPostProcessor> nonOrderedPostProcessors 
  2.     = new ArrayList<>(nonOrderedPostProcessorNames.size());
  3.     for (String postProcessorName : nonOrderedPostProcessorNames) {
  4.         nonOrderedPostProcessors.add(beanFactory.getBean(postProcessorName
  5.                                                          , BeanFactoryPostProcessor.class));
  6.     }
  7.     invokeBeanFactoryPostProcessors(nonOrderedPostProcessors, beanFactory);

最终清除缓存

  1. beanFactory.clearMetadataCache();