SpringMvc - 拦截器

springmvc-servlet.xml

    <!--配置拦截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            <!--拦截user下的所有请求 /user/**-->
            <mvc:mapping path="/user/**"/>
            <!--不拦截user下的/user/add请求-->
            <mvc:exclude-mapping path="/user/add"/>
            <!--注册拦截器-->
            <bean class="com.levi.config.LoginInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>

com.levi.config.LoginInterceptor

/*
* 拦截器
* 实现HandlerInterceptor 重写方法
* */
public class LoginInterceptor implements HandlerInterceptor {
    /*请求执行之前执行*/
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("请求执行之前 执行");
        /*true：放行 false：拦截*/
        return true;
    }

    /*请求执行之后执行*/
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("请求执行之后 执行");
    }

    /*请求执行 postHandle方法执行完之后执行 清理的作用*/
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("清理");
    }
}