設置session過濾器

 

package com.util;

import java.io.IOException;
import java.util.Map;

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;

public class SessionFilter implements Filter
{
    public void init(FilterConfig filterConfig) throws ServletException
    {
    }
   
    @SuppressWarnings("unchecked")
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException
    {
        HttpServletRequest req = (HttpServletRequest)request;
        HttpServletResponse res = (HttpServletResponse)response;
       
        HttpSession session = req.getSession(true);
       
        String url = req.getRequestURI();
       
        if (url.endsWith(".action"))
        {
            if (url.endsWith("login.action"))
            {
                chain.doFilter(request, response);
                return;
            }
            //從session裏取的用戶名信息
            Map customerUser = (Map)session.getAttribute("customerUser");
            Map whomeUser = (Map)session.getAttribute("whomeUser");
           
            if (customerUser != null && !customerUser.isEmpty())
            {
                //已經登陸,繼續此次請求
                chain.doFilter(request, response);
                return;
            }
            else if (whomeUser != null && !whomeUser.isEmpty())
            {
                //已經登陸,繼續此次請求
                chain.doFilter(request, response);
                return;
            }
            else
            {
                //跳轉到登陸頁面
                res.sendRedirect(req.getContextPath());
                return;
            }
        }
        else
        {
            chain.doFilter(request, response);
            return;
        }
       
    }
   
    public void destroy()
    {
    }
}