AutoConfiguration加载顺序问题

看下面这两个例子，哪个bean会加载？

例1

/**
* AaAutoConfiguration先加载
*/
@Configuration
public class AaAutoConfiguration{
 @Bean
 @ConditionalOnMissingBean(name="testBeanName")
 public TestBean testBeanName(){
   return new TestBean();
 }
}
/**
* BbAutoConfiguration后加载
*/
@Configuration
public class BbAutoConfiguration{
 @Bean
 @ConditionalOnMissingBean(name="testBeanName")
 public TestBean2 testBeanName(){
   return new TestBean2();
 }
}

答案：AaAutoConfiguration#testBeanName

例2

/**
* AaAutoConfiguration先加载
*/
@Configuration
public class AaAutoConfiguration{
 @Bean
 @ConditionalOnMissingBean(name="testBeanName")
 public TestBean testBeanName(){
   return new TestBean();
 }
}
/**
* BbAutoConfiguration后加载
*/
@Configuration
public class BbAutoConfiguration{
 @Bean
 @ConditionalOnMissingBean
   public TestBean2 testBeanName(){
   return new TestBean2();
 }
}

答案：BbAutoConfiguration#testBeanName

为什么呢？

触发问题条件：Bean ClassType 不一样+ConditionalOnMissingBean未指定name

查看spring代码 ConfigurationClassBeanDefinitionReader#loadBeanDefinitionsForBeanMethod方法

具体代码 conditionEvaluator.shouldSkip(metadata, ConfigurationPhase.REGISTER_BEAN)

    内部调用 ConditionalOnMissingBean的判断逻辑

    根据注解配置 ，先判断类型 ->再判断annotaion→最后判断beanNames（判断排除ignoreTypes）

    如果未匹配到，覆盖beanDefinition