Mule 4 DataWeave需求：动态统计唯一错误消息及出现次数

输入负载 #

[
   {
    "Error": "Quote is Mandatory;"
   },
   {
    "Error": "Quote is Mandatory;"
   },
   {
    "Error": "OrderForm is canceled"
   },
   {
    "Error": "Dealer not found"
   }
]

预期输出 #

[
     {
      "Error": "Quote is Mandatory;",
      "count": 2
     },
     {
      "Error": "OrderForm is canceled",
      "count": 1
     },
     {
      "Error": "Dealer not found",
      "count": 1
     }
]

DataWeave 代码实现 #

%dw 2.0
output application/json
---
payload groupBy ($.Error) 
    mapObject ((value, key) -> {
        Error: key,
        count: sizeOf(value)
    })
    pluck $

代码说明 #

• groupBy：按Error字段的值对输入数组分组，把相同错误消息的对象归为同一组。
• mapObject：遍历分组结果，将分组的键（错误消息）和分组内对象的数量（出现次数）组装成新对象。
• pluck $：将分组后的对象结构转换为数组结构，匹配预期输出的格式。

内容的提问来源于stack exchange，提问作者Devendra