spring3注解方式无法注入servlet和filter

filter和servlet不受spring管理，所以不能依赖注入spring管理的bean,在servlet里的init方法加入如下代码：

private XxxxService xxxxService;

WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(config.getServletContext());

xxxxService= (XxxxService) wac.getBean("xxxxService");

即可获得spring管理的bean.

filter代码如下：

wac = WebApplicationContextUtils.getRequiredWebApplicationContext(config.getServletContext());

xxxxService= (XxxxService) wac.getBean("xxxxService");