如何使用NiFi Jolt Specification重构Bets数组生成Outcomes子数组？

输入JSON数据 #

{
  "transaction_id": 53279810162,
  "bets": [
    {
      "event_name": "Mawkhar Sc - Rangdajied United FC (live)",
      "match_start": "1660905000000",
      "game_name": "Handicap ? £",
      "outcome_name": "2 (3:0)"
    },
    {
      "event_name": "University Azzurri Fc - Hellenic Athletic Club (live)",
      "match_start": "1660905000000",
      "game_name": "Handicap ? £",
      "outcome_name": "2 (3:0)"
    }
  ],
  "user_id": 1009425,
  "bet_type": "Multi"
}

期望输出JSON数据 #

{
  "transaction_id": 53279810162,
  "bets": [
    {
      "event_name": "Mawkhar Sc - Rangdajied United FC (live)",
      "match_start": "1660905000000",
      "outcomes": [
        {
          "outcome_name": "2 (3:0)",
          "game_name": "Handicap ? £"
        }
      ]
    },
    {
      "event_name": "University Azzurri Fc - Hellenic Athletic Club (live)",
      "match_start": "1660905000000",
      "outcomes": [
        {
          "outcome_name": "2 (3:0)",
          "game_name": "Handicap ? £"
        }
      ]
    }
  ],
  "user_id": 1009425,
  "bet_type": "Multi"
}

Jolt转换规范 #

使用Shift转换类型，对应的规范如下：

[
  {
    "operation": "shift",
    "spec": {
      "*": "&",
      "bets": {
        "*": {
          "event_name": "bets[&1].event_name",
          "match_start": "bets[&1].match_start",
          "game_name": "bets[&1].outcomes[0].game_name",
          "outcome_name": "bets[&1].outcomes[0].outcome_name"
        }
      }
    }
  }
]

规范说明 #

• *": "&"：保留根节点下除bets外的所有字段（如transaction_id、user_id、bet_type），直接映射到输出的同名字段。
• bets数组遍历：通过"*"遍历每个bets元素，&1代表当前数组元素的索引，确保每个元素对应输出中bets数组的对应位置。
• 保留原有字段：将每个bet里的event_name和match_start直接映射到输出的对应位置。
• 构建outcomes数组：把game_name和outcome_name放入outcomes数组的第一个元素（[0]）中，实现嵌套数组的结构。

内容的提问来源于stack exchange，提问作者3vge