如何通过Jolt转换将items的folderId替换为对应folders的name

输入示例 #

{
  "folders": [
    {
      "id": "folder_1",
      "name": "文档文件夹"
    },
    {
      "id": "folder_2",
      "name": "图片文件夹"
    }
  ],
  "items": [
    {
      "id": "item_1",
      "folderId": "folder_1"
    },
    {
      "id": "item_2",
      "folderId": "folder_2"
    },
    {
      "id": "item_3",
      "folderId": "folder_1"
    }
  ]
}

期望输出 #

{
  "folders": [
    {
      "id": "folder_1",
      "name": "文档文件夹"
    },
    {
      "id": "folder_2",
      "name": "图片文件夹"
    }
  ],
  "items": [
    {
      "id": "item_1",
      "folderId": "文档文件夹"
    },
    {
      "id": "item_2",
      "folderId": "图片文件夹"
    },
    {
      "id": "item_3",
      "folderId": "文档文件夹"
    }
  ]
}

可行Jolt规则 #

[
  {
    "operation": "shift",
    "spec": {
      "folders": {
        "*": {
          "id": "folderMap.&",
          "name": "folderMap.&"
        }
      },
      "items": "items",
      "*": "&"
    }
  },
  {
    "operation": "shift",
    "spec": {
      "items": {
        "*": {
          "id": "items.[&1].id",
          "folderId": {
            "@(2,folderMap.&)": "items.[&1].folderId"
          }
        }
      },
      "folders": "folders",
      "*": "&"
    }
  },
  {
    "operation": "remove",
    "spec": {
      "folderMap": ""
    }
  }
]

规则解析 #

• 第一步：构建文件夹键值映射
  通过shift操作把folders数组转换成folderMap对象，以文件夹的id为键、name为值，方便后续快速匹配。同时保留原items数组和其他顶层字段。

• 第二步：替换folderId字段
  遍历items数组的每个元素：

  • 保留id字段不变；
  • 用@(2,folderMap.&)语法，向上两层获取folderMap，并以当前folderId的值为键取出对应的文件夹名称，替换原folderId字段。

• 第三步：清理临时数据
  通过remove操作删除临时生成的folderMap对象，得到最终结构。

内容的提问来源于stack exchange，提问作者namtab