HierarchicalBeanFactory 提供父容器的访问功能.至于父容器的设置,需要找ConfigurableBeanFactory的setParentBeanFactory(接口把设置跟获取给拆开了!).
HierarchicalBeanFactory源码具体：

1、第一个方法返回本Bean工厂的父工厂。这个方法实现了工厂的分层。

2、第二个方法判断本地工厂是否包含这个Bean（忽略其他所有父工厂）。这也是分层思想的体现。

总结：这个工厂接口非常简单，实现了Bean工厂的分层。这个工厂接口也是继承自BeanFacotory，也是一个二级接口，相对于父接口，它只扩展了一个重要的功能——工厂分层。

/*** Sub-interface implemented by bean factories that can be part* of a hierarchy.** <p>The corresponding {@code setParentBeanFactory} method for bean* factories that allow setting the parent in a configurable* fashion can be found in the ConfigurableBeanFactory interface.** @author Rod Johnson* @author Juergen Hoeller* @since 07.07.2003* @see org.springframework.beans.factory.config.ConfigurableBeanFactory#setParentBeanFactory*/
public interface HierarchicalBeanFactory extends BeanFactory {/*** Return the parent bean factory, or {@code null} if there is none.*/// //  返回本Bean工厂的父工厂BeanFactory getParentBeanFactory();/*** Return whether the local bean factory contains a bean of the given name,* ignoring beans defined in ancestor contexts.* <p>This is an alternative to {@code containsBean}, ignoring a bean* of the given name from an ancestor bean factory.* @param name the name of the bean to query* @return whether a bean with the given name is defined in the local factory* @see BeanFactory#containsBean*///  本地工厂(容器)是否包含这个Beanboolean containsLocalBean(String name);}