/// 手动将JSON转换为有序的json字符串
static private func orderedJsonString(json: [String: Any]) -> String {
    var orderString = "{"
    let sortedKeys = json.keys.sorted { (key1, key2) -> Bool in
        return key1.lowercased() < key2.lowercased() // 按照字母排序Key
    }
    for key in sortedKeys {
        let keyStr = "\"\(key)\""
        let value = json[key]
        if let str = value as? String { // 如果是字符串，则在value前后加上"，并将\n替换为\\n，否则\n符号会被直接显示为空格，而后端需要
            orderString += (keyStr + ":" + "\"\(str)\"".replacingOccurrences(of: "\n", with: "\\n") + ",")
        } else if let arr = value as? NSArray { // 如果是数组
            // 如果数组里面是JSON，才排序，其他的用原顺序
            let orderArr = arr.sortedArray { (obj1, obj2) -> ComparisonResult in
                return .orderedDescending
            }
            if let strArr = arr as? [String] {  // 字符串数组
                let orderStrArr = strArr.map { "\($0)" }
                orderString += (keyStr + ":" + "\(orderStrArr)".replacingOccurrences(of: " ", with: "") + ",") // 将空格去掉，去掉Swift传参时元素间自动添加的空格。可以进一步优化：自己去拼出来，因为目前会把内容中的空格也去掉
            } else if let dictArr = orderArr as? [[String: Any]] { // 如果是JSON，手动拼出来，详见arrayJsonString
                let arrJsonStr = arrayJsonString(arr: dictArr)
                orderString += (keyStr + ":" + arrJsonStr + ",")
            } else {        // 其他类型，直接赋值
                orderString += (keyStr + ":" + "\(arr)" + ",")
            }
        } else if let dict = value as? [String: Any] {  // 如果是JSON，则递归得出json字符串
            let jsonStr = orderedJsonString(json: dict)
            orderString += (keyStr + ":" + "\(jsonStr)" + ",")
        } else { // Int, Double等number类型  // if let num = value as? Int
            orderString += (keyStr + ":" + "\(value ?? 0)" + ",")
        }
    }
    orderString = orderString.subString(to: orderString.count - 1)
    orderString += "}"

    return orderString
}

/// 将JSON数组类型拼接为字符串，手动处理""和\\，防止使用上述方法出现的多“或多\的情况
static private func arrayJsonString(arr: [[String: Any]]) -> String {
    var arrStr = "["
    for a in arr {
        let jsonStr = orderedJsonString(json: a)
        arrStr += (jsonStr + ",")
    }
    arrStr = arrStr.subString(to: arrStr.count - 1)
    arrStr += "]"
    return arrStr
}