1 public static void invokeBeanFactoryPostProcessors(
2 ConfigurableListableBeanFactory beanFactory, List<BeanFactoryPostProcessor> beanFactoryPostProcessors) {
3
4 // Invoke BeanDefinitionRegistryPostProcessors first, if any.
5 Set<String> processedBeans = new HashSet<>();
6 //先判断是否是beanFactory的实例-都是
7 if (beanFactory instanceof BeanDefinitionRegistry) {
8 BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
9 List<BeanFactoryPostProcessor> regularPostProcessors = new ArrayList<>();
10 List<BeanDefinitionRegistryPostProcessor> registryProcessors = new ArrayList<>();
11 //beanFactoryPostProcessors 是通过addBeanFactoryPostProcessor加进来的,如果实现了BeanDefinitionRegistryPostProcessor，
12 //立马执行postProcessBeanDefinitionRegistry(),优先级最高
13 //区别：BeanDefinitionRegistryPostProcessor用来添加额外的bd，而BeanFactoryPostProcessor用来修改bd
14 for (BeanFactoryPostProcessor postProcessor : beanFactoryPostProcessors) {
15 if (postProcessor instanceof BeanDefinitionRegistryPostProcessor) {
16 BeanDefinitionRegistryPostProcessor registryProcessor =
17 (BeanDefinitionRegistryPostProcessor) postProcessor;
18 registryProcessor.postProcessBeanDefinitionRegistry(registry);
19 registryProcessors.add(registryProcessor);
20 }
21 else {
22 regularPostProcessors.add(postProcessor);
23 }
24 }
25
26 // Do not initialize FactoryBeans here: We need to leave all regular beans
27 // uninitialized to let the bean factory post-processors apply to them!
28 // Separate between BeanDefinitionRegistryPostProcessors that implement
29 // PriorityOrdered, Ordered, and the rest.
30 List<BeanDefinitionRegistryPostProcessor> currentRegistryProcessors = new ArrayList<>();
31
32 // First, invoke the BeanDefinitionRegistryPostProcessors that implement PriorityOrdered.
33 //只有一个类：ConfigurationClassPostProcessor
34 //createApplicationContext会通过反射生成AnnotationConfigApplicationContext实例
35 // AnnotationConfigApplicationContext无参构造函数中会通过RootBeanDefinition来注册ConfigurationClassPostProcessor、
36 // AutowiredAnnotationBeanPostProcessor、CommonAnnotationBeanPostProcessor、PersistenceAnnotationBeanPostProcessor、EventListenerMethodProcessor、DefaultEventListenerFactory
37 String[] postProcessorNames =
38 beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
39 for (String ppName : postProcessorNames) {
40 if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
41 currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
42 processedBeans.add(ppName);
43 }
44 }
45 sortPostProcessors(currentRegistryProcessors, beanFactory);
46 registryProcessors.addAll(currentRegistryProcessors);
47 //开始解析ConfigurationClassPostProcessor，到这里才会扫描获取其他bean产生beanDefinitionMap,这个类会解析spring.factories、@Import @CompanScan @Bean 等注解
48 invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
49 currentRegistryProcessors.clear();
50
51 // Next, invoke the BeanDefinitionRegistryPostProcessors that implement Ordered.
52 //这里可以看出PriorityOrdered的优先级比Ordered高
53 //重新调用方面获取postProcessorNames的原因：
54 //上面解析ConfigurationClassPostProcessor完成后会增加新的实现BeanDefinitionRegistryPostProcessor的类，所以要重新获取
55 postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
56 for (String ppName : postProcessorNames) {
57 if (!processedBeans.contains(ppName) && beanFactory.isTypeMatch(ppName, Ordered.class)) {
58 currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
59 processedBeans.add(ppName);
60 }
61 }
62 sortPostProcessors(currentRegistryProcessors, beanFactory);
63 registryProcessors.addAll(currentRegistryProcessors);
64 invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
65 currentRegistryProcessors.clear();
66
67 // Finally, invoke all other BeanDefinitionRegistryPostProcessors until no further ones appear.
68 //之后调用即没有实现PriorityOrdered也没有实现Ordered的BeanDefinitionRegistryPostProcessors类
69 boolean reiterate = true;
70 while (reiterate) {
71 reiterate = false;
72 //需要重新获取postProcessorNames，原因和之前一样
73 postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
74 for (String ppName : postProcessorNames) {
75 //之前已经解析过的不再解析
76 if (!processedBeans.contains(ppName)) {
77 currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
78 processedBeans.add(ppName);
79 reiterate = true;
80 }
81 }
82 sortPostProcessors(currentRegistryProcessors, beanFactory);
83 registryProcessors.addAll(currentRegistryProcessors);
84 invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
85 currentRegistryProcessors.clear();
86 }
87
88 // Now, invoke the postProcessBeanFactory callback of all processors handled so far.
89 //调用实现BeanDefinitionRegistryPostProcessor的类的postProcessBeanFactory方法
90 invokeBeanFactoryPostProcessors(registryProcessors, beanFactory);
91 //调用由通过addBeanFactoryPostProcessor加进来的实现BeanFactoryPostProcessor接口的类的方法
92 //BeanDefinitionRegistryPostProcessor extends BeanFactoryPostProcessor 所以addBeanFactoryPostProcessor2个接口的实现类都可以加
93 invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory);
94 }
95
96 else {
97 // Invoke factory processors registered with the context instance.
98 invokeBeanFactoryPostProcessors(beanFactoryPostProcessors, beanFactory);
99 }
100
101 // Do not initialize FactoryBeans here: We need to leave all regular beans
102 // uninitialized to let the bean factory post-processors apply to them!
103 //这个之后就会调用直接实现BeanFactoryPostProcessor接口的类，调用规则和上面一样，
104 //先调用实现了PriorityOrdered，再调用Ordered,再调用2个都没有的实现了BeanFactoryPostProcessor接口的类
105 String[] postProcessorNames =
106 beanFactory.getBeanNamesForType(BeanFactoryPostProcessor.class, true, false);
107
108 // Separate between BeanFactoryPostProcessors that implement PriorityOrdered,
109 // Ordered, and the rest.
110 List<BeanFactoryPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
111 List<String> orderedPostProcessorNames = new ArrayList<>();
112 List<String> nonOrderedPostProcessorNames = new ArrayList<>();
113 for (String ppName : postProcessorNames) {
114 if (processedBeans.contains(ppName)) {
115 // skip - already processed in first phase above
116 }
117 else if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
118 priorityOrderedPostProcessors.add(beanFactory.getBean(ppName, BeanFactoryPostProcessor.class));
119 }
120 else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
121 orderedPostProcessorNames.add(ppName);
122 }
123 else {
124 nonOrderedPostProcessorNames.add(ppName);
125 }
126 }
127
128 // First, invoke the BeanFactoryPostProcessors that implement PriorityOrdered.
129 sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
130 invokeBeanFactoryPostProcessors(priorityOrderedPostProcessors, beanFactory);
131
132 // Next, invoke the BeanFactoryPostProcessors that implement Ordered.
133 List<BeanFactoryPostProcessor> orderedPostProcessors = new ArrayList<>(orderedPostProcessorNames.size());
134 for (String postProcessorName : orderedPostProcessorNames) {
135 orderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
136 }
137 sortPostProcessors(orderedPostProcessors, beanFactory);
138 invokeBeanFactoryPostProcessors(orderedPostProcessors, beanFactory);
139
140 // Finally, invoke all other BeanFactoryPostProcessors.
141 List<BeanFactoryPostProcessor> nonOrderedPostProcessors = new ArrayList<>(nonOrderedPostProcessorNames.size());
142 for (String postProcessorName : nonOrderedPostProcessorNames) {
143 nonOrderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
144 }
145 invokeBeanFactoryPostProcessors(nonOrderedPostProcessors, beanFactory);
146
147 // Clear cached merged bean definitions since the post-processors might have
148 // modified the original metadata, e.g. replacing placeholders in values...
149 beanFactory.clearMetadataCache();
150 }
