springmvc的拦截器interceptpr相当于servlet的过滤器filter
按顺序联结 形成拦截器链
步骤：
1.创建拦截器实现handleinterceptor接口
package com.itheima.intercept;import org.springframework.lang.Nullable;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class MyIntercept implements HandlerInterceptor {//目标方法执行之前public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {System.out.println("preHandle...");return true;}//目标方法执行后、视图对象返回前public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {System.out.println("postHandle...");}//整个流程执行完毕后public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {System.out.println("afterCompletion...");}
}
2.配置拦截器
<mvc:interceptors><mvc:interceptor><!--对哪些资源执行--><mvc:mapping path="/**"/><bean class="com.itheima.intercept.MyIntercept"/></mvc:interceptor> </mvc:interceptors>
3.测试拦截器效果