如何在Mule中将输入JSON数组转换为指定格式的CSV？

Got it, let's tackle this custom conversion in Mule using DataWeave 2.0—this is the standard tool for transformations in Mule 4+, and it'll handle this perfectly. Here's a step-by-step breakdown and working script:

Step 1: Group Data by Gender #

First, we'll group your input JSON array using the gender field. This lets us bundle all "F" and "M" entries separately, which aligns with your desired output structure.

Step 2: Format Segments and Combine #

Next, we'll format each group into the required string chunks, then stitch everything together with your specified delimiter **|**.

Full DataWeave Script #

%dw 2.0
output application/text
var groupedData = payload groupBy $.gender
// Define group order to match your expected output (F first, then M)
var groupOrder = ["F", "M"]
---
groupOrder flatMap (gender) -> do {
    // Sort entries by ID descending to match your sample output order
    var sortedEntries = groupedData[gender] orderBy -$.id
    var formattedEntries = sortedEntries map ("$(name)*$(id)")
    // Combine gender header with formatted entries
    ["gender:$(gender)"] ++ formattedEntries
} joinBy "**|**" ++ "**|**"

Test with Your Input #

When you feed your input JSON array:

[ 
  { "id":"001", "name":"john", "gender": "M" }, 
  { "id":"002", "name":"Mule", "gender": "F" }, 
  { "id":"003", "name":"Sara", "gender": "F" }, 
  { "id":"004", "name":"Mati", "gender": "F" } 
]

You'll get exactly the output you're expecting:

gender:F**|**Mati*004**|**Sara*003**|**Mule*002**|**gender:M**|**john*001**|**

How It Works #

• groupBy $.gender: Groups the input into an object where keys are "F"/"M" and values are the matching entry arrays.
• groupOrder: Forces us to process "F" entries first, then "M" to match your output sequence.
• orderBy -$.id: Sorts entries within each group by ID descending, which gives you the "Mati004" → "Sara003" → "Mule*002" order from your sample.
• flatMap: Builds the header string for each group, then maps every entry to the "name*id" format.
• joinBy "**|**": Glues all segments together with your delimiter.
• ++ "**|**": Adds the trailing delimiter as seen in your desired output.

If you need to adjust the entry order (e.g., sort by name instead of ID), just modify the orderBy clause—swap -$.id with $.name to sort alphabetically, for example.

内容的提问来源于stack exchange，提问作者Amira