HttpServletRequest請求擷取用戶端的IP位址

直接上代碼:

public static String getIpAddr(HttpServletRequest request) {
		String ip = request.getHeader("X-Real-IP");
		if (StringUtils.isNotBlank(ip) && !"unknown".equalsIgnoreCase(ip)) {
			return ip;
		}
		ip = request.getHeader("X-Forwarded-For");
		if (StringUtils.isNotBlank(ip) && !"unknown".equalsIgnoreCase(ip)) {
			// 多次反向代理後會有多個IP值，第一個為真實IP。
			int index = ip.indexOf(',');
			if (index != -1) {
				return ip.substring(0, index);
			} else {
				return ip;
			}
		} else {
			return request.getRemoteAddr();
		}
	}