获取springMvc中的bean

<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>context</servlet-name>
<servlet-class>org.springframework.web.context.ContextLoaderServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet>
<servlet-name>SpringMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/applicationContext-servlet.xml</param-value>
<load-on-startup>1</load-on-startup>
</init-param>
</servlet>

web.xml配置信息（举例），以下是我获取bean的方法

ApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(request.getServletContext());
DialManageService dialManageService = (DialManageService)context.getBean("DialManageService");

结果报以下异常

2016-07-08 14:07:12,328 ERROR [http-bio-8080-exec-5] ManageToolsController - --dialTest error --
org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'DialManageService' is defined
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:698)
at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1174)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:283)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1045)

简单说就是获取不到这个bean，试了几次还是这样的错，感觉应该是不再同一个上下文，在网上找了下，发现下面的帖子有有用信息
http://bbs.csdn.net/topics/390977647
原来springMvc和spring上下文不是同一个，spring是用listener初始化的上下文，称为root上下文，springMvc是通过servlet初始化的上下文，称为servlet上下文，servlet里的能获取root里的，反之就获取不到，servlet应该是root的子上下文，而我获取bean的地方是处于root上下文的，怎么才能通过代码获取servlet的上下文呢？帖子里给我满意的答案，于是我修改代码如下

ApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(request.getServletContext(),

"org.springframework.web.servlet.FrameworkServlet.CONTEXT.SpringMVC");
DialManageService dialManageService = (DialManageService)context.getBean("DialManageService");

WebApplicationContextUtils.getWebApplicationContext（）方法的第二个参数，其中SpringMVC是servlet上下文配置的servlet名字，这样获取到的上下文就是servlet上下文，这样就能成功获取到这个bean，如果现在用这个context获取root上下文的bean就获取不到了，很有用，记录下