AnnotationConfigUtils这个工具类具有什么功能呢?

AnnotationConfigUtils工具类

`AnnotationConfigUtils`是Spring框架中一个工具类
  这个工具类用于处理注解配置相关的任务
   它提供一系列静态方法
    帮助Spring容器解析和注册与注解配置相关Bean 定义 
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常见AnnotationConfigUtils工具类的功能
- 注册`BeanFactoryPostProcessor`:
    处理`@PropertySource`和`@ComponentScan`等注解。
- 注册`BeanPostProcessor`：
    处理`@Autowired`、`@PostConstruct` 等注解。
- 处理`@Import` 注解：
    解析`@Import`注解并注册相应的 Bean 定义。
- 处理`@ComponentScan` 注解：
    扫描并注册指定包中的组件

`AnnotationConfigUtils`主要功能和用途

1.注册注解配置处理器

`AnnotationConfigUtils`提供方法来注册处理注解配置的处理器
例
`ConfigurationClassPostProcessor`
这是 Spring 注解配置的核心处理器之一。

例：
  注册 `ConfigurationClassPostProcessor`
 
import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;

public class AnnotationConfigUtilsExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();
        AnnotationConfigUtils.registerAnnotationConfigProcessors(context);
        context.refresh();
    }
}
 
2.注册`CommonAnnotationBeanPostProcessor`

`CommonAnnotationBeanPostProcessor` 
处理 `@PostConstruct`、`@PreDestroy` 和 `@Resource` 注解。

注册`CommonAnnotationBeanPostProcessor`

import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;

public class CommonAnnotationBeanPostProcessorExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();
        AnnotationConfigUtils.registerCommonAnnotationBeanPostProcessor(context);
        context.refresh();
    }
}

3.注册`AutowiredAnnotationBeanPostProcessor`
`AutowiredAnnotationBeanPostProcessor`处理`@Autowired` 和 `@Value` 注解。

例：注册`AutowiredAnnotationBeanPostProcessor`
import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;

public class AutowiredAnnotationBeanPostProcessorExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();
        AnnotationConfigUtils.registerAutowiredAnnotationBeanPostProcessor(context);
        context.refresh();
    }
}
 
4.注册`RequiredAnnotationBeanPostProcessor` 
`RequiredAnnotationBeanPostProcessor`
  处理`@Required`注解 

例：
  注册`RequiredAnnotationBeanPostProcessor`

import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;

public class RequiredAnnotationBeanPostProcessorExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();
        AnnotationConfigUtils.registerRequiredAnnotationBeanPostProcessor(context);
        context.refresh();
    }
}

5.注册`PersistenceAnnotationBeanPostProcessor`
`PersistenceAnnotationBeanPostProcessor`处理JPA相关的注解
  如 `@PersistenceContext` 和 `@PersistenceUnit` 

 例：注册 `PersistenceAnnotationBeanPostProcessor`
 
import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;

public class PersistenceAnnotationBeanPostProcessorExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();
        AnnotationConfigUtils.registerPersistenceAnnotationBeanPostProcessor(context);
        context.refresh();
    }
}
 
 6.注册 `EventlistenerMethodProcessor` 和 `DefaultEventListenerFactory`
这些处理器用于处理 `@EventListener` 注解。

例：注册 `EventListenerMethodProcessor` 和 `DefaultEventListenerFactory`

import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;

public class EventListenerExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();
        AnnotationConfigUtils.registerAnnotationConfigProcessors(context);
        context.refresh();
    }
}

7.注册`ApplicationListenerDetector`
`ApplicationListenerDetector`用于检测
  并注册实现`ApplicationListener`接口Bean

例：注册`ApplicationListenerDetector`

import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;

public class ApplicationListenerDetectorExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();
        AnnotationConfigUtils.registerApplicationListenerDetector(context);
        context.refresh();
    }
}

8.注册`BeanPostProcessor` 和 `BeanFactoryPostProcessor`
`AnnotationConfigUtils` 还提供方法来注册自定义的 `BeanPostProcessor` 和 `BeanFactoryPostProcessor`。

例：注册自定义`BeanPostProcessor`

import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;
import org.springframework.beans.factory.config.BeanPostProcessor;

public class CustomBeanPostProcessorExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();
        AnnotationConfigUtils.registerAnnotationConfigProcessors(context);
        context.registerBean("customBeanPostProcessor", CustomBeanPostProcessor.class);
        context.refresh();
    }

    static class CustomBeanPostProcessor implements BeanPostProcessor {
        @Override
        public Object postProcessBeforeInitialization(Object bean, String beanName) {
            System.out.println("Before Initialization: " + beanName);
            return bean;
        }

        @Override
        public Object postProcessAfterInitialization(Object bean, String beanName) {
            System.out.println("After Initialization: " + beanName);
            return bean;
        }
    }
}

AnnotationConfigUtils例

import org.springframework.context.annotation.AnnotationConfigUtils;
import org.springframework.context.support.GenericApplicationContext;

public class AnnotationConfigUtilsExample {
    public static void main(String[] args) {
        GenericApplicationContext context = new GenericApplicationContext();

        // 注册注解配置处理器
        AnnotationConfigUtils.registerAnnotationConfigProcessors(context);
        AnnotationConfigUtils.registerCommonAnnotationBeanPostProcessor(context);
        AnnotationConfigUtils.registerAutowiredAnnotationBeanPostProcessor(context);
        AnnotationConfigUtils.registerRequiredAnnotationBeanPostProcessor(context);
        AnnotationConfigUtils.registerPersistenceAnnotationBeanPostProcessor(context);
        AnnotationConfigUtils.registerApplicationListenerDetector(context);

        // 刷新上下文
        context.refresh();

        // 输出已注册的 Bean 定义名称
        String[] beanNames = context.getBeanDefinitionNames();
        for (String beanName : beanNames) {
            System.out.println("Bean Definition Name: " + beanName);
        }

        // 关闭上下文
        context.close();
    }
}

===============================输出示例===================================
 
Bean Definition Name: org.springframework.context.annotation.internalConfigurationAnnotationProcessor
Bean Definition Name: org.springframework.context.annotation.internalAutowiredAnnotationProcessor
Bean Definition Name: org.springframework.context.annotation.internalRequiredAnnotationProcessor
Bean Definition Name: org.springframework.context.annotation.internalCommonAnnotationProcessor
Bean Definition Name: org.springframework.context.event.internalEventListenerProcessor
Bean Definition Name: org.springframework.context.event.internalEventListenerFactory
Bean Definition Name: org.springframework.context.annotation.internalPersistenceAnnotationProcessor
Bean Definition Name: org.springframework.context.annotation.internalAnnotationPostProcessor
Bean Definition Name: org.springframework.context.annotation.internalApplicationListenerDetector