sessionfilter.java

关于servlet的很全的例子,对学习servlet很有帮助的,大家

package com.allanlxf.sms.web;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

public class SessionFilter implements Filter
{
    private FilterConfig config;
    
    public void init(FilterConfig config) throws ServletException
    {
        this.config = config;
    }
    
    public void doFilter(ServletRequest request, ServletResponse response,
                   FilterChain chain) throws IOException, ServletException
    {
        HttpServletRequest httpRequest = (HttpServletRequest)request;
        HttpServletResponse httpResponse = (HttpServletResponse)response;
        
        HttpSession session = httpRequest.getSession(false);
        if(session == null)
        {
            httpResponse.sendRedirect(httpRequest.getContextPath() + "/login");
            return;
        }
        
        chain.doFilter(request, response);
    }
    
    public void destroy()
    {
    }
}