spring的拦截器(MethodInterceptor)做权限验证，如何判断session里是否有值

spring的拦截器(MethodInterceptor)做权限验证，怎么判断session里是否有值
spring的拦截器(MethodInterceptor)做权限验证，判断session里是否有值，可是拦截器里得不到session啊，怎么办？

public class chkLoginAdvice implements MethodInterceptor{
//得不到session啊
}

[解决办法]
public class xxxSessionInterceptor extends HandlerInterceptorAdapter
{
public boolean preHandle(HttpServletRequest request,HttpServletResponse response,Object handler) 


这里处理就可以~