如何在MuleSoft中筛选满足子对象条件的完整对象

我是MuleSoft新手，需要从给定的JSON Payload中筛选出完整的Offer对象，要求该对象的characters[].data[]数组中存在"name":"priority"且"value":1的项。以下是相关内容：

JSON Payload #

{
  "offers": [
    {
      "id": 100,
      "name": "Test1",
      "category": {
        "characters": [
          {
            "data": [
              {
                "name": "priority",
                "value": 1
              },
              {
                "type": "ILL",
                "result": "pass"
              }
            ]
          }
        ]
      }
    },
    {
      "id": 200,
      "name": "Test2",
      "category": {
        "characters": [
          {
            "data": [
              {
                "name": "priority",
                "value": 2
              },
              {
                "type": "ILL",
                "result": "Fail"
              }
            ]
          }
        ]
      }
    },
    {
      "id": 300,
      "name": "Test3",
      "category": {
        "characters": [
          {
            "data": [
              {
                "name": "priority",
                "value": 3
              },
              {
                "type": "ILL",
                "result": "Pass"
              }
            ]
          }
        ]
      }
    }
  ]
}

预期结果 #

{
  "id": 100,
  "name": "Test1",
  "category": {
    "characters": [
      {
        "data": [
          {
            "name": "priority",
            "value": 1
          },
          {
            "type": "ILL",
            "result": "pass"
          }
        ]
      }
    ]
  }
}

尝试过的不符合需求的代码 #

(payload.offers map {
    (($$): $) if((flatten($.category.characters.data) filter ((item, index) -> item.name=="WBB" and item.priority==1)))
}) - {}

解决方案 #

你的代码存在两处关键错误：一是过滤条件里的item.name=="WBB"应该改为"priority"，二是判断优先级值时用了item.priority，但原数据里对应的属性是item.value。另外，用map结合条件的方式不够直接，推荐用filter来筛选数组：

筛选出所有符合条件的Offer（返回数组） #

%dw 2.0
output application/json
---
payload.offers filter ((offer) -> 
    flatten(offer.category.characters.data) any ((item) -> 
        item.name == "priority" and item.value == 1
    )
)

仅返回第一个符合条件的Offer（匹配你的预期结果） #

%dw 2.0
output application/json
---
(payload.offers filter ((offer) -> 
    flatten(offer.category.characters.data) any ((item) -> 
        item.name == "priority" and item.value == 1
    )
))[0]

代码说明 #

1. filter：遍历offers数组，保留满足条件的元素
2. flatten(offer.category.characters.data)：将嵌套的characters.data数组展开成一维数组，方便后续判断
3. any：检查展开后的数组中是否存在至少一个符合name="priority"且value=1的项，只要存在就保留当前Offer
4. [0]：如果只需要第一个匹配的对象，在筛选后的数组后加上该索引即可

内容的提问来源于stack exchange，提问作者Krish