package com.chen.filter;

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

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;
import javax.servlet.http.HttpServletRequest;

public class MyFilter implements Filter {

	private FilterConfig filterConfig;

	@Override
	public void destroy() {

	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		ServletContext context = filterConfig.getServletContext();
		Map<String, Integer> ipMap = (Map<String, Integer>) context
				.getAttribute("ipMap");
		String ip = request.getRemoteAddr();
//		String ip = getIpAddr(request);
		if (ipMap.containsKey(ip)) {
			Integer count = ipMap.get(ip);
			ipMap.put(ip, count + 1);
		} else {
			ipMap.put(ip, 1);
		}
		context.setAttribute("ipMap", ipMap);
		chain.doFilter(request, response);
	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig;
	}

	public String getIpAddr(HttpServletRequest request)  {
        String ip  =  request.getHeader( " x-forwarded-for " );
         if (ip  ==   null   ||  ip.length()  ==   0   ||   " unknown " .equalsIgnoreCase(ip))  {
            ip  =  request.getHeader( " Proxy-Client-IP " );
        } 
         if (ip  ==   null   ||  ip.length()  ==   0   ||   " unknown " .equalsIgnoreCase(ip))  {
            ip  =  request.getHeader( " WL-Proxy-Client-IP " );
        } 
         if (ip  ==   null   ||  ip.length()  ==   0   ||   " unknown " .equalsIgnoreCase(ip))  {
           ip  =  request.getRemoteAddr();
       } 
        return  ip;
   }
}