/**
	 * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址。
	 * 可是，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，究竟哪个才是真正的用户端的真实IP呢？
	 * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串
	 * @param request
	 * @return
	 */
	public static String getIpAddress(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.getHeader("HTTP_CLIENT_IP");
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("HTTP_X_FORWARDED_FOR");
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getRemoteAddr();
			if("127.0.0.1".equals(ip)||"0:0:0:0:0:0:0:1".equals(ip)){
				//根据网卡取本机配置的IP
				InetAddress inet=null;
				try {
					inet = InetAddress.getLocalHost();
				} catch (UnknownHostException e) {
					//e.printStackTrace();
				}
				ip= inet.getHostAddress();
			}
		}
		return ip;
	}