SpringMvc第六篇【拦截器】

    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <mvc:exclude-mapping path="/login"/>
            <bean class="com.example.demo.config.MyInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>

package com.example.demo.config;

import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        Object user = request.getSession().getAttribute("user");
        if (user == null) {
            response.sendRedirect("/login.jsp");
            return false;
        } else {
            return true;
        }
    }
}