java session过期跳转_Session过期后自动跳转到登录页面

最近研究如果用原生的Filter来判别session存在否或者过期否。来跳转到的页面实例，下载来展示代码。

因为顾虑器是每次请求能会进入的，所以可以设置了，进行拦截判断

1.配置web.xml

BackEndFilter

com.sun.BackFilter

BackFilter

/backend/issues/*

/backend/repairmen/*

/backend/payment/*

2.新建BackFilter类，实现Filter接口。

package com.xyt.backend;

import java.io.IOException;

import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import com.xyt.common.Logging;

import com.xyt.common.RedisClient;

import com.xyt.jdbc.entity.Admin;

/**

* 后台管理系统登录拦截器

*/

public class BackFilter implements Filter {

@Override

public void init(FilterConfig filterConfig) throws ServletException {

//useless

}

@Override

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)

throws IOException, ServletException {

HttpSession sess = ((HttpServletRequest)request).getSession();

String ad = sess.getAttribute("admin");

if(ad==null ){

((HttpServletResponse)response).sendRedirect(((HttpServletRequest)request).getContextPath()+"//login");

}else{

chain.doFilter(request, response);

}

}

@Override

public void destroy() {

//useless

}

}