获得客户端真实IP的方法

	/**
	 * 取得客户端真实ip
	 * 
	 * @param request
	 * @return 客户端真实ip
	 */
	public String getIpAddr(HttpServletRequest request) {
		String ip = request.getHeader("X-Forwarded-For");
		logger.debug("1- X-Forwarded-For ip={}", ip);
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("Proxy-Client-IP");
			logger.debug("2- Proxy-Client-IP ip={}", ip);
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("WL-Proxy-Client-IP");
			logger.debug("3- WL-Proxy-Client-IP ip={}", ip);
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("HTTP_CLIENT_IP");
			logger.debug("4- HTTP_CLIENT_IP ip={}", ip);
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("HTTP_X_FORWARDED_FOR");
			logger.debug("5- HTTP_X_FORWARDED_FOR ip={}", ip);
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getRemoteAddr();
			logger.debug("6- getRemoteAddr ip={}", ip);
		}
		logger.info("finally ip={}", ip);
		return ip;
	}