spring mvc 拦截器

public class HandlerInterceptor1 implements org.springframework.web.servlet.HandlerInterceptor {

    /**
     *
     * @param request
     * @param response
     * @param handler
     * @return true: 放行，执行下一个拦截器 ；
     *         false：不放行，直接跳转到某页面，不执行对应的controller方法
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("拦截器1执行了.....前");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("拦截器1执行了...后");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("拦截器1执行了...加载");
    }
}