Question

我在这里有这个JSON：

  [{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ -2.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 1.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, 2.3458776596, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ -5.449212707644754, 2.3458776596, -1.452433 ]
  }]

表示图表中的点列表。在这种情况下，我们给定时间戳有三个点，所以这个JSON描述了三个图（三个通道）。

这适用于普通通道（即简单浮点值列表）。到目前为止一切都很好。

不幸的是，在某些情况下，我们有所谓的“minmax”通道，其中每个点都表示为一对浮点数！

让我们拿最后一个例子，将中间通道（第二个）替换为“minmax”通道。这里的问题是我不知道如何JSON-ize这个“minmax”通道的浮动对没有歧义。

  [{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ -2.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 1.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ 0.449212707644754, ???, 1.452433 ]
  },
  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ -5.449212707644754, ???, -1.452433 ]
  }]

最好的方法是什么？我可以在其他数组中包含未命名的数组吗？那么在Javascript对象中反序列化这样的JSON呢？

Answer 1

您可以在此部分嵌套数组，如下所示：

没有minimax：

  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ [0.449212707644754], [1.11111], [1.452433] ]
  },

使用minimax：

  {
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [ [0.449212707644754], [1.11111, 1.63245345], [1.452433] ]
  },

然后在解析时，您只需要检查第二个通道有多少个数组元素，这样就可以确定它是否为极小极大值。当然，它与第一和第三频道完全相同。

键入时，数组表示为打开和关闭括号： []其中可能包含以逗号分隔的值列表[“a”，“b”，“c”]。这些值可以是任何JSON数据类型：string，number，boolean， object，array，null。资料来源：https://www.json.com/json-array

Answer 2

如果频道具有某些含义，您还可以考虑使用以下架构，并替换df -i，first和second名称以更好地描述频道。

third

该解决方案的出现具有更好的可读性。很明显，{ "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68", "DateTime": "2014-05-13T09:24:49", "Channels": { "first": { "value": -5.449212707644754 }, "second": { "min": 0.312, "max": 1.2312321 }, "third": { "value": -1.452433 } } }和min是什么意思。如果你使用嵌套数组，没有人会知道它是＆＃34; minmax＆＃34;信道

Answer 3

使您的频道值成为一个对象数组。这样，您可以命名这些对象的属性，而不是依赖它们的位置来指示它们的含义。 e.g。

{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [
        { 
            value: -2.449212707644754
        },
        { 
            min: -2.449212707644754,
            max: 4.678432425151,
        },
        { 
            value: 1.452433
        }
    ]
}

关于JSON数据大小，大多数Web服务器将允许您启用HTTP响应的压缩，浏览器将自动解压缩。这在服务器端非常容易启用。压缩JSON与二进制协议一样小，例如Google Protocol Buffers。在这种情况下，JSON中将存在大量冗余，因此它应该非常好地压缩。您也可以将属性命名为单个字符。例如v表示值，n表示最小值，x表示最大值

{
    "HistoryId": "bf39d7cfca8536b3e00e5355dff25a97715bc439a5c73d41d10a9eb0c45f2e68",
    "DateTime": "2014-05-13T09:24:49",
    "ChannelsValues": [
        { 
            v: -2.449212707644754
        },
        { 
            n: -2.449212707644754,
            x: 4.678432425151,
        },
        { 
            v: 1.452433
        }
    ]
}

如何改进我的JSON架构？

3 个答案: