負載均衡後微信支付：invalid spbill_create_ip錯誤

微信支付時需要向微信傳送一個spbill_create_ip的參數，開發的時候我們是從request中通過如下代碼方式獲取到的

    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();
        }
        String realIp = ip.equals("0:0:0:0:0:0:0:1") ? "127.0.0.1" : ip;
        return realIp;
    }

然後正常單臺部署時沒問題，今天在阿里雲加入負載均衡並啓用https後微信支付莫名就不能用了（下單失敗不能生成二維碼），異常如下：｛微信返回returnCode:FAIL,返回returnMsg:invalid spbill_create_ip"}"}，經過分析發現是加了負載均衡且啓用https後request中的IP地址被修改成了兩個不一樣的地址數組了（具體是因爲加負載引起的還是因爲https引起的，還是兩個一起引起的還不確定）。然後果斷對獲取到的“IP”地址進行處理後（改爲取第一個地址）支付恢復正常。