此篇代码在jdk11上正常运行，springBoot版本为2.7.14

1.容器与 bean

1.BeanFactory 接口

1.先看下源码：

2.从源码中的接口中可以得出结论：BeanFactory 主要就是处理Bean的，典型的功能有getBean();

2.ApplicationContext 接口

1.先看下源码：

2.ApplicationContext 接口，是 BeanFactory 的子接口。它扩展了 BeanFactory 接口的功能

3.看下结构图

2.测试几个小案例

1.debug看下启动类，我们可以看到BeanFactory 为ApplicationContext 的一个变量

2.测试获取spring.factories中的代码

public static void main(String[] args) throws Exception {
    ConfigurableApplicationContext context = SpringApplication.run(DomeApplication.class, args);
    Resource[] resources = context.getResources("classpath*:META-INF/spring.factories");
    for (Resource resource : resources) {
        System.out.println(resource);
    }
}

3.测试获取单例池

public static void main(String[] args) throws Exception {
    ConfigurableApplicationContext context = SpringApplication.run(DomeApplication.class, args);

    Field singletonObjects = DefaultSingletonBeanRegistry.class.getDeclaredField("singletonObjects");
    singletonObjects.setAccessible(true);
    ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
    Map<String, Object> map = (Map<String, Object>) singletonObjects.get(beanFactory);
    map.forEach((k, v) -> {
        System.out.println(k + " : " + v);
    });
}

4.测试监听

1.继承ApplicationEvent

public class jianting extends ApplicationEvent {
    public jianting(Object source) {
        super(source);
    }
}

2.接收消息代码

@Component
public class test_shou {
    @EventListener
    public void aaa(jianting aa){
        System.out.println(aa);
    }
}

3.发消息

public static void main(String[] args) throws Exception {
   ConfigurableApplicationContext context = SpringApplication.run(DomeApplication.class, args);
   context.publishEvent(new jianting("发消息"));
}