ApplicationContext解析

ApplicationContext 这个接口作为作为spring框架下最重要的一个接口他提供了能力结构图如上。

他自己提供了以下方法

public interface ApplicationContext extends EnvironmentCapable, ListableBeanFactory, HierarchicalBeanFactory,
		MessageSource, ApplicationEventPublisher, ResourcePatternResolver {

	/**
	 * 返回这个context的唯一id
	 */
	@Nullable
	String getId();

	/**
	 * 返回这个context所属的应用名称
	 */
	String getApplicationName();

	/**
	 * 返回一个context名称
	 */
	String getDisplayName();

	/**
	 * 返回context加载的时间
	 */
	long getStartupDate();

	/**
	 * 返回级的上下文
	 */
	@Nullable
	ApplicationContext getParent();

	/**
	 * 公开AutowireCapableBeanFactory接口的能力给到context
	 * 
This is not typically used by application code, except for the purpose of
	 * initializing bean instances that live outside of the application context,
	 * applying the Spring bean lifecycle (fully or partly) to them.
	 * 
Alternatively, the internal BeanFactory exposed by the
	 * {@link ConfigurableApplicationContext} interface offers access to the
	 * {@link AutowireCapableBeanFactory} interface too. The present method mainly
	 * serves as a convenient, specific facility on the ApplicationContext interface.
	 * 
NOTE: As of 4.2, this method will consistently throw IllegalStateException
	 * after the application context has been closed. In current Spring Framework
	 * versions, only refreshable application contexts behave that way; as of 4.2,
	 * all application context implementations will be required to comply.
	 * @return the AutowireCapableBeanFactory for this context
	 * @throws IllegalStateException if the context does not support the
	 * {@link AutowireCapableBeanFactory} interface, or does not hold an
	 * autowire-capable bean factory yet (e.g. if {@code refresh()} has
	 * never been called), or if the context has been closed already
	 * @see ConfigurableApplicationContext#refresh()
	 * @see ConfigurableApplicationContext#getBeanFactory()
	 */
	AutowireCapableBeanFactory getAutowireCapableBeanFactory() throws IllegalStateException;