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

目录

• 1. 要研究的代码
  
• 2. 获取所有类型为BeanPostProcessor的PostProcessor
  
• 3. 遍历分成PriorityOrdered、MergedBeanDefinitionPostProcessor、Ordered、普通的四类
  
• 4. 排序、把实现了PriorityOrdered的BeanPostProcessor加入到bean工厂里
  
• 5. 排序、把实现了Ordered的BeanPostProcessor加入到bean工厂里
  
• 6. 排序、把普通的BeanPostProcessor加入到bean工厂里
  
• 7. 排序、把MergedBeanDefinitionPostProcessor类型的BeanPostProcessor加入到bean工厂里
  

1. 要研究的代码

• AbstractApplicationContext registerBeanPostProcessors
  

1. protected void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory) {
2.         //传入当前bean工厂,注册BeanPostProcessor并调用postProcess方法
3.         PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this);
4. }

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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）
  

1. public static void registerBeanPostProcessors(
2.                 ConfigurableListableBeanFactory beanFactory, AbstractApplicationContext applicationContext) {
4.         //从bean工厂中获取类型为BeanPostProcessor的PostProcssor
5.         String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);
7.         // Register BeanPostProcessorChecker that logs an info message when
8.         // a bean is  
9.         // a bean is not eligible for getting processed by all BeanPostProcessors.
10.         int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
11.         beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));
13.         // Separate between BeanPostProcessors that implement PriorityOrdered,
14.         // Ordered, and the rest.
15.         List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
16.         List<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>();
17.         List<String> orderedPostProcessorNames = new ArrayList<String>();
18.         List<String> nonOrderedPostProcessorNames = new ArrayList<String>();
19.         //遍历所有PostProcessor，分为PriorityOrdered、MergedBeanDefinitionPostProcessor、Ordered、普通的四类
20.         for (String ppName : postProcessorNames) {
21.                 if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
22.                         BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
23.                         priorityOrderedPostProcessors.add(pp);
24.                         if (pp instanceof MergedBeanDefinitionPostProcessor) {
25.                                 internalPostProcessors.add(pp);
26.                         }
27.                 }
28.                 else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
29.                         orderedPostProcessorNames.add(ppName);
30.                 }
31.                 else {
32.                         nonOrderedPostProcessorNames.add(ppName);
33.                 }
34.         }
36.         // First, register the BeanPostProcessors that implement PriorityOrdered.
37.         //排序、把实现了PriorityOrdered的BeanPostProcessor加入到bean工厂里
38.         sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
39.         registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);
41.         // Next, register the BeanPostProcessors that implement Ordered.
42.         //排序、把实现了Ordered的BeanPostProcessor加入到bean工厂里
43.         List<BeanPostProcessor> orderedPostProcessors = new ArrayList<BeanPostProcessor>();
44.         for (String ppName : orderedPostProcessorNames) {
45.                 BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
46.                 orderedPostProcessors.add(pp);
47.                 if (pp instanceof MergedBeanDefinitionPostProcessor) {
48.                         internalPostProcessors.add(pp);
49.                 }
50.         }
51.         sortPostProcessors(orderedPostProcessors, beanFactory);
52.         registerBeanPostProcessors(beanFactory, orderedPostProcessors);
54.         // Now, register all regular BeanPostProcessors.
55.         //排序、把普通的BeanPostProcessor加入到bean工厂里
56.         List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
57.         for (String ppName : nonOrderedPostProcessorNames) {
58.                 BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
59.                 nonOrderedPostProcessors.add(pp);
60.                 if (pp instanceof MergedBeanDefinitionPostProcessor) {
61.                         internalPostProcessors.add(pp);
62.                 }
63.         }
64.         registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);
66.         // Finally, re-register all internal BeanPostProcessors.
67.         ////排序、把MergedBeanDefinitionPostProcessor类型的BeanPostProcessor加入到bean工厂里
68.         sortPostProcessors(internalPostProcessors, beanFactory);
69.         registerBeanPostProcessors(beanFactory, internalPostProcessors);
71.         // Re-register post-processor for detecting inner beans as ApplicationListeners,
72.         // moving it to the end of the processor chain (for picking up proxies etc).
73.         //最后加入一个ApplicationListenerDetector
74.         beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));
75. }

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2. 获取所有类型为BeanPostProcessor的PostProcessor

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

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

1. List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
2. List<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>();
3. List<String> orderedPostProcessorNames = new ArrayList<String>();
4. List<String> nonOrderedPostProcessorNames = new ArrayList<String>();
5. //遍历所有PostProcessor，分为PriorityOrdered、MergedBeanDefinitionPostProcessor、Ordered、普通的四类
6. for (String ppName : postProcessorNames) {
7.     if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
8.         BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
9.         priorityOrderedPostProcessors.add(pp);
10.         if (pp instanceof MergedBeanDefinitionPostProcessor) {
11.             internalPostProcessors.add(pp);
12.         }
13.     }
14.     else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
15.         orderedPostProcessorNames.add(ppName);
16.     }
17.     else {
18.         nonOrderedPostProcessorNames.add(ppName);
19.     }
20. }

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

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

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

1. // Next, register the BeanPostProcessors that implement Ordered.
2. //排序、把实现了Ordered的BeanPostProcessor加入到bean工厂里
3. List<BeanPostProcessor> orderedPostProcessors = new ArrayList<BeanPostProcessor>();
4. for (String ppName : orderedPostProcessorNames) {
5.     BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
6.     orderedPostProcessors.add(pp);
7.     if (pp instanceof MergedBeanDefinitionPostProcessor) {
8.         internalPostProcessors.add(pp);
9.     }
10. }
11. sortPostProcessors(orderedPostProcessors, beanFactory);
12. registerBeanPostProcessors(beanFactory, orderedPostProcessors);

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6. 排序、把普通的BeanPostProcessor加入到bean工厂里

1. // Now, register all regular BeanPostProcessors.
2. //排序、把普通的BeanPostProcessor加入到bean工厂里
3. List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanPostProcessor>();
4. for (String ppName : nonOrderedPostProcessorNames) {
5.     BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
6.     nonOrderedPostProcessors.add(pp);
7.     if (pp instanceof MergedBeanDefinitionPostProcessor) {
8.         internalPostProcessors.add(pp);
9.     }
10. }
11. registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);

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

1. // Finally, re-register all internal BeanPostProcessors.
2. ////排序、把MergedBeanDefinitionPostProcessor类型的BeanPostProcessor加入到bean工厂里
3. sortPostProcessors(internalPostProcessors, beanFactory);
4. registerBeanPostProcessors(beanFactory, internalPostProcessors);

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