由于weblogic的javax.servlet.XXX.jar跟tomcat提供的servlet-api.jar文件有些差别
所以在获得servletContext的时候，方式有点不同
weblogic: session.getServletContext()
tomcat: request.getServletContext()
SpringMVC & DWR:
WebContextFactory.get().getSession()
WebContextFactory.get().getSessionContext()
WebContextFactory.get().getRequest()
WebContextFactory.get().getServletContext()
http://panyongzheng.iteye.com/admin/blogs/1263411