在json4s结构中添加其他字段

Question

我试图在json4s结构中添加一个额外的字段，但文档只描述了removeField和transformField。缺少类似addField的东西。 所以，我有的json输入是：

{
  "layers": [
    {
      "name": "geometry",
      "layerProperties": [
        {
          "name": "Schema-Layer",
          "value": "schema"
        },
        {
          "name": "Schema-Proto-Bundle",
          "value": "geometry"
        },
        {
          "name": "Compression",
          "value": "true"
        },
        {
          "name": "Content-Type",
          "value": "application/x-protobuf"
        }
      ]
    },
    {
      "name": "schema",
      "layerProperties": [
        {
          "name": "Content-Type",
          "value": "application/zip"
        }
      ]
    },
    {
      "name": "state",
      "layerProperties": [
        {
          "name": "Compression",
          "value": "true"
        }
      ]
    },
    {
      "name": "history",
      "layerProperties": [
        {
          "name": "Content-Type",
          "value": "application/json"
        }
      ]
    }
  ]
}

我需要实现这个目标：

{
  "layers": [
    {
      "name": "geometry",
      "dataUrl": "s3://somebucket/somepath",
      "layerProperties": [
        {
          "name": "Schema-Layer",
          "value": "schema"
        },
        {
          "name": "Schema-Proto-Bundle",
          "value": "geometry"
        },
        {
          "name": "Compression",
          "value": "true"
        },
        {
          "name": "Content-Type",
          "value": "application/x-protobuf"
        }
      ]
    },
    {
      "name": "schema",
      "dataUrl": "s3://somebucket/somepath",
      "layerProperties": [
        {
          "name": "Content-Type",
          "value": "application/zip"
        }
      ]
    },
    {
      "name": "state",
      "dataUrl": "s3://somebucket/somepath",
      "layerProperties": [
        {
          "name": "Compression",
          "value": "true"
        }
      ]
    },
    {
      "name": "history",
      "dataUrl": "s3://somebucket/somepath",
      "layerProperties": [
        {
          "name": "Content-Type",
          "value": "application/json"
        }
      ]
    }
  ]
}

那么，每一层都需要有一个dataUrl fieldAny ideas？