获取客户端真实IP地址

1、需要引入log4j-1.2.14.jar

package org.ydd.test;


import java.util.Enumeration;

import javax.servlet.http.HttpServletRequest;

import org.apache.log4j.Logger;

/**
 * @author coco
 * @version 
 * 获取IP4
 */
public class IP4 {
	private static final Logger log = Logger.getLogger(IP4.class);
	/**
	 * 获取客户端真实IP地址（注意：如果通过Squid反向代理软件，需更改squid.conf配置文件forwarded_for项默认是为on，
	 * 否则获取到的IP为unknown）
	 * @param request
	 * @return
	 */
	@SuppressWarnings({ "rawtypes", "unchecked" })
	public  static String getIpAddr(HttpServletRequest request) {
	log.debug("====================================================");

	if(log.isDebugEnabled()){
	StringBuffer buf = new StringBuffer("all head info:\n");
	Enumeration enumeration = request.getHeaderNames();
	while(enumeration.hasMoreElements()){
	Object head = enumeration.nextElement();
	if(null != head){
	String value = request.getHeader(String.valueOf(head));
	buf.append(head + "=" + value + "\n");
	}
	}
	log.debug(buf.toString());
	}

	String ip = request.getHeader("x-forwarded-for");
	log.debug("request.getHeader(\"x-forwarded-for\")=" + ip);

	if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
	ip = request.getHeader("X-Forwarded-For");
	log.debug("request.getHeader(\"X-Forwarded-For\")=" + ip);
	}

	if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
	ip = request.getHeader("Proxy-Client-IP");
	log.debug("request.getHeader(\"Proxy-Client-IP\")=" + ip);
	}

	if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
	ip = request.getHeader("WL-Proxy-Client-IP");
	log.debug("request.getHeader(\"WL-Proxy-Client-IP\")=" + ip);
	}

	if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
	ip = request.getHeader("HTTP_CLIENT_IP");
	log.debug("request.getHeader(\"HTTP_CLIENT_IP\")=" + ip);
	}

	if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
	ip = request.getHeader("HTTP_X_FORWARDED_FOR");
	log.debug("request.getHeader(\"HTTP_X_FORWARDED_FOR\")=" + ip);
	}

	if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
	ip = request.getRemoteAddr();
	log.debug("request.getRemoteAddr()=" + ip);
	}

	if(null != ip && ip.indexOf(',') != -1){
	//如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串 IP 值
	//取X-Forwarded-For中第一个非unknown的有效IP字符串
	//如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130, 192.168.1.100
	//用户真实IP为： 192.168.1.110 
	//注意:当访问地址为 localhost 时 地址格式为 0:0:0:0:0:0:1
	log.debug("ip=" + ip);
	String[] ips = ip.split(",");
	for (int i = 0; i < ips.length; i++) {
	if(null != ips[i] && !"unknown".equalsIgnoreCase(ips[i])){
	ip = ips[i];
	break;
	}
	}
	if("0:0:0:0:0:0:1".equals(ip)){
	log.warn("由于客户端访问地址使用 localhost，获取客户端真实IP地址错误，请使用IP方式访问");
	}
	}

	if("unknown".equalsIgnoreCase(ip)){
	log.warn("由于客户端通过Squid反向代理软件访问，获取客户端真实IP地址错误，请更改squid.conf配置文件forwarded_for项默认是为on解决");
	}
	log.debug("====================================================");
	return ip;
	}
}