java 获取真实IP

public String getIp() {
	String ip = request.getHeader("x-forwarded-for");
	if(ip == null || ip.length() == 0 || "unknow".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 ();
		if (ip.equals ("127.0.0.1")) {
			//根据网卡取本机配置的IP
			InetAddress inet = null;
			try {
				inet = InetAddress.getLocalHost ();
			} catch (Exception e) {
				e.printStackTrace ();
			}
			ip = inet.getHostAddress ();
		}
	}
	// 多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
	if (ip != null && ip.length () > 15) {
		if (ip.indexOf (",") > 0) {
			ip = ip.substring (0, ip.indexOf (","));
		}
	}
	return ip;
}