【Spring源码】AutowiredAnnotationBeanPostProcessor.postProcessMergedBeanDefinition()详解

爱被打了一巴掌 2024-03-30 17:30 147阅读 0赞

【Spring源码系列- IOC】

<table style=""> 
 <tbody> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">1</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/124325005" rel="nofollow">【Spring源码】0.安装Gradle环境</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">2</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/124295132" rel="nofollow">【Spring源码】1.下载与编译_pom relocation to an other version number is not f</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">3</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/124494757" rel="nofollow">【Spring源码】2.试个水先～Debug找到传说中的三级缓存(图解向，堆图预警)</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">4</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/124494175" rel="nofollow">【Spring源码】3. xml文件如何转换成BeanDefinition(主要涉及prepareRefresh()+ obtainFreshBeanFactory()两个函数，图解向，堆图预警)_spring xml转bean</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">5</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/124967341" rel="nofollow">【Spring源码】4. 自己搞个标签?~自定义标签保姆级全过程(图解向，堆图预警)</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">6</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/125099022" rel="nofollow">【Spring源码】5.spring的bean工厂准备工作（prepareBeanFactory(beanFactory)</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">7</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/125099608" rel="nofollow">【Spring源码】6. Spring扩展自定义属性编辑器保姆级教程</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">8</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/125189197" rel="nofollow">【Spring源码】7. 如何添加自定义的BeanFactoryPostProcessor</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">9</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/125913768" rel="nofollow">【Spring源码】8. 捋下invokeBeanFactoryPostProcessors()主要处理流程</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">10</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/126053792" rel="nofollow">【Spring源码】9. 超级重要的ConfigurationClassPostProcessor</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">11</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/126107551" rel="nofollow">【Spring源码】10. 递归调用的processConfigurationClass()方法</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">12</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/126107412" rel="nofollow">【Spring源码】11. 我是注解类不？checkConfigurationClassCandidate()注解类判断方法详解</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">13</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/126136230" rel="nofollow">【Spring源码】12. 注册bean处理器registerBeanPostProcessors()</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">14</td> 
 <td style="width:313px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/126303691" rel="nofollow">【Spring源码】13. 国际化处理initMessageSource()源码解析</a></td> 
 <td style="width:455px;vertical-align:middle;height:52px;">【补充内容】<a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/127171568" rel="nofollow">【保姆级】SpringBoot项目中的i18n国际化</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">15</td> 
 <td style="width:313px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/126644051" rel="nofollow">【Spring源码】14. 消息多播器（观察者模式）</a></td> 
 <td style="width:455px;vertical-align:middle;height:52px;">【补充内容】<a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/126127883" rel="nofollow">【保姆级示例向】观察者模式</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">16</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/127362286" rel="nofollow">【Spring源码】15. Bean的创建过程（1.概述篇）</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">17</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/127432109" rel="nofollow">【Spring源码】16. Bean的创建过程（2）</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">18</td> 
 <td style="width:313px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/127472470" rel="nofollow">【Spring源码】17.创建Bean这篇认真的@(・●・)@</a></td> 
 <td style="width:455px;vertical-align:middle;height:52px;">【补充内容】<a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128188799" rel="nofollow">【保姆级·创建对象】如何通过Supplier创建对象</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128204883" rel="nofollow">【保姆级·创建对象】如何通过factory-method创建对象</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/127865881" rel="nofollow">【保姆级·创建对象】如何利用resolveBeforeInstantiation()在预处理阶段返回一个Bean的实例对象</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">19</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128002786" rel="nofollow">【Spring源码】18. factory-method创建对象关键函数详解：instantiateUsingFactoryMethod()</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">20</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128632696" rel="nofollow">【Spring源码】19. 没合适的构造器？找determineCandidateConstructors()！</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">21</td> 
 <td style="width:313px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128633664" rel="nofollow">【Spring源码】20. MergedBeanDefinitionPostProcessor修改/合并bean定义</a></td> 
 <td style="width:455px;vertical-align:middle;height:52px;">【补充内容】<a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128633923" rel="nofollow">【保姆级】@PostConstruct &amp; @PreDestroy使用示例</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128644949" rel="nofollow">【Spring源码】AutowiredAnnotationBeanPostProcessor.postProcessMergedBeanDefinition()详解</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128644909" rel="nofollow">【Spring源码】CommonAnnotationBeanPostProcessor.postProcessMergedBeanDefinition()详解</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:49px;">22</td> 
 <td style="width:313px;vertical-align:middle;height:49px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128656295" rel="nofollow">【Spring源码】21. 初探循环依赖</a></td> 
 <td style="width:455px;vertical-align:middle;height:49px;">【补充内容】<a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128702039" rel="nofollow">【保姆级】手把手Debug循环依赖的整体流程</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128715562" rel="nofollow">【实践向】当移除了三级缓存……</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128775251" rel="nofollow">【分析向】没有三级缓存会导致什么？</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128785050" rel="nofollow">【Spring源码】插播一个创建代理对象的wrapIfNecessary()方法</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">23</td> 
 <td style="width:313px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128800736" rel="nofollow">【Spring源码】22. 属性填充populateBean()详解</a></td> 
 <td style="width:455px;vertical-align:middle;height:52px;">【补充内容】<a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128812119" rel="nofollow">【Spring源码】自动注入·名称：autowireByName()详解</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128905209" rel="nofollow">【Spring源码】自动注入·类型：autowireByType()详解</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128922136" rel="nofollow">【Spring源码】属性值的解析与赋值：populateBean().applyPropertyValues()</a><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128938759" rel="nofollow">【保姆级】超超超简单的自定义注解实现@Autowired同款功能</a></td> 
 </tr> 
 <tr> 
 <td style="width:60px;vertical-align:middle;height:52px;">24</td> 
 <td colspan="2" style="width:768px;vertical-align:middle;height:52px;"><a style="color:#0A6CFF;" href="https://blog.csdn.net/aqin1012/article/details/128949267" rel="nofollow">【Spring源码】23. 执行初始化逻辑：initializeBean()</a></td> 
 </tr> 
 </tbody> 
</table>

像之前介绍CommonAnnotationBeanPostProcessor一样的，我们进入applyMergedBeanDefinitionPostProcessors()方法中的循环中，当遍历的BeanPostProcessor为AutowiredAnnotationBeanPostProcessor时，就开始了我们这篇文章⁄(⁄ ⁄ ⁄ω⁄ ⁄ ⁄)⁄～～～

![e8c6d057d34f41b31e2daa8962285eb6.png][]

进入bdp.postProcessMergedBeanDefinition*(*mbd, beanType, beanName*)，*找到AutowiredAnnotationBeanPostProcessor实现类

![c6ae3944b573fdf938d4318fb5aab60e.png][]

于是我们来到了AutowiredAnnotationBeanPostProcessor.postProcessMergedBeanDefinition()

![5b29bf14abfc4ad41ca66470eb346a23.png][]

### findAutowiringMetadata() ###

![10d29e7018d50ce7a15a38b2e88829b4.png][]

方法中，先从缓存中获取该类的信息，进而根据获取到的metadata判断是否需要刷先缓存，如果需要则通过构建buildAutowiringMetadata()方法自动装配的属性和方法元数据

#### buildAutowiringMetadata() ####

先判断给定的类是否带有指定的注解

![d6409d022a755429de0dfbe4008b292d.png][]

这里的autowiredAnnotationTypes会在AutowiredAnnotationBeanPostProcessor的构造函数中进行赋值

![1c93506078bae9e0d3896c2595cc3284.png][]

从上图可以看到autowiredAnnotationTypes包含3个对象：

*  Autowired.class

*  Value.class

* (Class<? extends Annotation>) ClassUtils.forName("javax.inject.Inject", AutowiredAnnotationBeanPostProcessor.class.getClassLoader())

前两个大家应该很熟悉（最后一个俺也不熟先不管他(˶‾᷄ ⁻̫ ‾᷅˵)），随后就开始了一个do\{ \}while()循环♻️

![910db7abbc353f44c7e0edd3b8eb2b22.png][]

每次循环中进行了4个步骤：

1.  先判断属性

遍历类中的每个属性，通过方法findAutowiredAnnotation()判断属性是否包含指定的注解，如果存在则保存为AutowriedFieldElement

注意⚠️@Autowried注解不支持静态属性

1.  再判断方法

遍历类中的每个方法，通过方法findAutowiredAnnotation()判断方法是否包含指定的注解，如果存在则保存为AutowriedMerthodElement

注意⚠️@Autowried注解不支持静态方法

1.  接着把他们添加进集合

1.  最后获取其父类，直到其父类为空或者为Object.class结束循环

![962b1bb49e374776f3be4867519e3710.png][]

##### findAutowiredAnnotation() #####

在这个方法中会循环判断，但凡有一个属性/方法上标记了指定注解，就会立刻返回

![85c25e2c0aa1977780fac9232cd46b1c.png][]

[e8c6d057d34f41b31e2daa8962285eb6.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/cc45606607844480ba9cf8ec2cd79724.png
[c6ae3944b573fdf938d4318fb5aab60e.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/31070b92c96847278bc5526bb7a0aceb.png
[5b29bf14abfc4ad41ca66470eb346a23.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/2840cc77b50440598d3c1fb79553223d.png
[10d29e7018d50ce7a15a38b2e88829b4.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/047c20616fdd47fe8a14798a02b55b1a.png
[d6409d022a755429de0dfbe4008b292d.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/ceab0083c4de4a668844a72215aa9a49.png
[1c93506078bae9e0d3896c2595cc3284.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/546ca146e8a54cf7829d2cc541ce6792.png
[910db7abbc353f44c7e0edd3b8eb2b22.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/e63273615ae94e569b0c4dea56a943a7.png
[962b1bb49e374776f3be4867519e3710.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/d733a2e31db04c099ce17d2722d29d1c.png
[85c25e2c0aa1977780fac9232cd46b1c.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/90c2173a69e44a10b9c579b905f709b1.png