如何编写Jolt规格，为嵌套数组对象添加父数组关联属性？

当然可以实现这个需求，以下是对应的Jolt规格以及详细说明：

输入JSON #

{
  "owners": [
    {
      "ownerId": "1",
      "ownerName": "Alice"
    },
    {
      "ownerId": "2",
      "ownerName": "Bob"
    }
  ],
  "children": [
    {
      "childId": "c1",
      "pets": [
        {
          "petId": "p1",
          "ownerId": "1"
        },
        {
          "petId": "p2",
          "ownerId": "2"
        }
      ]
    },
    {
      "childId": "c2",
      "pets": [
        {
          "petId": "p3",
          "ownerId": "1"
        }
      ]
    }
  ]
}

期望输出JSON #

{
  "owners": [
    {
      "ownerId": "1",
      "ownerName": "Alice"
    },
    {
      "ownerId": "2",
      "ownerName": "Bob"
    }
  ],
  "children": [
    {
      "childId": "c1",
      "pets": [
        {
          "petId": "p1",
          "ownerId": "1",
          "ownerName": "Alice"
        },
        {
          "petId": "p2",
          "ownerId": "2",
          "ownerName": "Bob"
        }
      ]
    },
    {
      "childId": "c2",
      "pets": [
        {
          "petId": "p3",
          "ownerId": "1",
          "ownerName": "Alice"
        }
      ]
    }
  ]
}

Jolt转换规格 #

[
  {
    "operation": "shift",
    "spec": {
      "owners": "owners",
      "children": {
        "*": {
          "childId": "children[&1].childId",
          "pets": {
            "*": {
              "@": "children[&3].pets[&1]",
              "@(4,owners[#ownerId].ownerName)": "children[&3].pets[&1].ownerName"
            }
          }
        }
      }
    }
  }
]

规格说明 #

• 直接保留原有owners数组的结构映射到输出字段
• 遍历children数组的每个元素：
  • 保留childId的字段映射
  • 遍历每个子项的pets数组：
    • 用@将当前pet的所有原有属性映射到对应位置
    • 通过@(4,owners[#ownerId].ownerName)完成关联匹配：
      • 4表示向上回溯4层路径，定位到根节点的owners数组
      • #ownerId表示以当前pet对象的ownerId值为索引，从owners数组中取出对应的ownerName

内容的提问来源于stack exchange，提问作者Rock