HandlerInterceptor是SpringMVC中为拦截器提供的接口，这个接口中需要有三个方法重写：
public class FG implements HandlerInterceptor{@Overridepublic void afterCompletion(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, Exception arg3)throws Exception {// TODO Auto-generated method stub}@Overridepublic void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,Object arg2, ModelAndView arg3) throws Exception {// TODO Auto-generated method stub}@Overridepublic boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1,Object arg2) throws Exception {// TODO Auto-generated method stubreturn false;}}说明：
preHandle
被拦截的controller执行之前的方法postHandle
被拦截的controller执行之后的方法afterCompletion
最终执行方法
要想最终写的拦截器生效，需要在Springmvc配置文件添加拦截器：
<!--配置拦截器 --><mvc:interceptors><mvc:interceptor><mvc:mapping path="需要拦截的链接"/><mvc:mapping path="需要拦截的链接/><bean class="写的拦截器的类的名称（全名称）"/></mvc:interceptor></mvc:interceptors>