DispatcherServlet被初始化的源头

web 服务器初始化：
首先SttpServletBean 继承了HttpServlet.
1.execute init method in class HttpServletBean。
2.init function call initServletBean method,it is in abstract class FrameworkServlet
3.initServletBean call initWebApplicationContext();
4.initWebApplicationContext call onRefresh()method.
5.DispatcherServlet extends FrameworkServlet,so over write method onRefresh().
6. onRefresh Call initStrategies
7.What has been inited plz check method initedStrategies.

应该是这个过程。