myebuyfilter.java

一个基于java工厂模式的 的实现

/*
 * MyebuyFilter.java
 *
 * Created on 2007年4月24日, 下午2:13
 */

package com.ebuy.web.filters;

import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
 *
 * @author  Administrator
 * @version
 */

public class MyebuyFilter implements javax.servlet.Filter
{
    
    public MyebuyFilter()
    {
    }
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain)
            throws IOException, ServletException
    {
        HttpServletRequest rq=(HttpServletRequest)request;
        HttpServletResponse rs=(HttpServletResponse)response;
        String path=rq.getContextPath();
        if(rq.getSession().getAttribute("customer")==null)
        {
            String url=rq.getRequestURI();
            String querystring=rq.getQueryString();
            if(querystring!=null)
            {
                url+="?";
                url+=querystring;
            }
            rq.getSession().setAttribute("returnURL",url);
            rs.sendRedirect(path+"/login.jsp");
        }
        else
        {
            chain.doFilter(request,response);
        }
    }
    public void destroy()
    {
    }
    
    public void init(FilterConfig filterConfig)
    {        
    }

    
    
}