ssm配置拦截器

在spring-mvc中使用标签

  <mvc:interceptors>
        <mvc:interceptor>
        
            <mvc:mapping path="/*"/>
            
            <mvc:exclude-mapping path="/login"/>
            <bean class="com.chen.interceptor.LoginInterceptor">bean>
        mvc:interceptor>
    mvc:interceptors>

创建自定义拦截器

package com.chen.interceptor;

import com.chen.entity.User;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpSession;

/**
 * Created by Administrator on 2017/2/21 0021.
 */
public class LoginInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Object handler) throws Exception {
       //首先进入的方法
        System.out.println("preHandle");
        //return false表示拦截，不向下执行
         //return true表示放行
        System.out.println(request.getServletPath());
        HttpSession session = request.getSession();
        User u=(User)session.getAttribute("userInfo");
        if(u!=null){
            return true;
        }else{
            return false;
        }

    }
    //返回modelAndView之前执行
    @Override
    public void postHandle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

        System.out.println("postHandle");
    }
    //执行Handler完成执行此方法
    @Override
    public void afterCompletion(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Object handler, Exception ex) throws Exception {

        System.out.println("afterCompletion");
    }
}