父子容器
<!--配置springmvc-->
<servlet>
<servlet-name>ssm</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>ssm</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!--加载spring容器-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext-*.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
父子容器关系： 子容器可以获取父容器的对象进行操作，父容器不能使用子容器存在
