bankpayfilter.java

一个基于java工厂模式的 的实现

/*
 * BankPayFilter.java
 *
 * Created on 2007年4月26日, 下午1:15
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package com.ebuy.web.filters;

import java.io.IOException;
import java.util.ArrayList;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Administrator
 */
public class BankPayFilter implements javax.servlet.Filter
{
    
    private ArrayList pathlist;
    
    public BankPayFilter()
    {
    }

    public void init(FilterConfig filterConfig) throws ServletException
    {
        this.pathlist=new ArrayList();
        ServletContext context=filterConfig.getServletContext();
        java.util.Enumeration<String> enums=context.getInitParameterNames();
        String name=null;
        String value=null;
        while(enums.hasMoreElements())
        {
           name=enums.nextElement();
           if(name.startsWith("bank"))
           {
               value=context.getInitParameter(name);
               pathlist.add(value.toLowerCase());
           }
        }
     }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException
    {
        HttpServletRequest rq=(HttpServletRequest)request;
        HttpServletResponse rs=(HttpServletResponse)response;        
        String sourcepath=rq.getHeader("referer");
        if(sourcepath==null || (!this.pathlist.contains(sourcepath.toLowerCase())))
        {
            String scirpt="<script>window.alert('你是个黑客!');window.opener='anyone';window.close();</script>";
            rs.getWriter().write(scirpt);
        }
        else
        {
            chain.doFilter(request,response);
        }
                
    }

    public void destroy()
    {
    }
    
}