如何通过DataWeave将含@前缀字段的JSON转为带属性的XML

在使用DataWeave 2.0将JSON转换为XML时，JSON中带@前缀的字段被错误转换为独立的XML标签（如<@id>1495144</@id>），需要将这些字段转为对应XML元素的属性。

示例请求JSON #

{
    "trans": {
        "@id": "1495144",
        "@TPId": "4aec",
        "@change": "0",
        "@count": "1",
        "@dateStamp": "2024-08-02T03:07:48",
        "data": {
            "@id": "d7D173564C5F14FF2AD08D621C188AF19",
            "StateFlag": "0",
            "DCC": "B",
            "LastName": "MMNGorthy",
            "Name": "Scott",
            "Structure": "NonProfit",
            "BusinessType": "Engineering",
            "meams": "AI",
            "Count": "0",
            "CTier": "000",
            "CTCond": "111",
            "CTPl": "222",
            "DO": "1",
            "AuthObject": "0"
        }
    }
}

现有DataWeave代码 #

%dw 2.0
output application/xml
ns ns0 http://Test.Sample.Data/1.0
---
ns0#trans: payload.trans

当前错误输出XML #

<?xml version='1.0' encoding='UTF-8'?>
<ns0:trans xmlns:ns0="http://Test.Sample.Data/1.0">
  <@id>1495144</@id>
  <@TPId>4aec</@TPId>
  <@change>0</@change>
  <@count>1</@count>
  <@dateStamp>2024-08-02T03:07:48</@dateStamp>
  <data>
    <@id>d7D173564C5F14FF2AD08D621C188AF19</@id>
    <StateFlag>0</StateFlag>
    <DCC>B</DCC>
    <LastName>MMNGorthy</LastName>
    <Name>Scott</Name>
    <Structure>NonProfit</Structure>
    <BusinessType>Engineering</BusinessType>
    <meams>AI</meams>
    <Count>0</Count>
    <CTier>000</CTier>
    <CTCond>111</CTCond>
    <CTPl>222</CTPl>
    <DO>1</DO>
    <AuthObject>0</AuthObject>
  </data>
</ns0:trans>

预期输出XML #

<?xml version='1.0' encoding='UTF-8'?>
<ns0:trans xmlns:ns0="http://Test.Sample.data/1.0" id="1495144" TPId='4aec' change='0' count='1' dateStamp="2024-08-02T03:07:48">
    <data id="d7D173564C5F14FF2AD08D621C188AF19">
        <StateFlag>0</StateFlag>
        <DCC>B</DCC>
        <LastName>MMNGorthy</LastName>
        <Name>Scott</Name>
        <Structure>NonProfit</Structure>
        <BusinessType>Engineering</BusinessType>
        <meams>AI</meams>
        <Count>0</Count>
        <CTier>000</CTier>
        <CTCond>111</CTCond>
        <CTPl>222</CTPl>
        <DO>1</DO>
        <AuthObject>0</AuthObject>
    </data>
</ns0:trans>

解决方案代码 #

通过递归处理JSON对象，分离@前缀字段并转换为XML属性（DataWeave中用@前缀标识XML属性），普通字段保留为子元素：

%dw 2.0
output application/xml
ns ns0 http://Test.Sample.Data/1.0

// 递归处理对象，分离属性和子元素
fun processXmlNode(obj) = 
    obj 
        // 拆分@开头的属性字段和普通子元素字段
        partition ((val, key) -> key startsWith "@")
        // 转换属性键名（去掉@）并转为XML属性格式，子元素递归处理
        mapObject ((group, groupKey) -> 
            if (groupKey == "0") {
                // 属性组：将键名的@去掉，用@前缀标记为XML属性
                (keys group map "@" ++ ($ replace "@" with "")) : values group
            } else {
                // 子元素组：递归处理嵌套对象
                (keys group) mapObject ((val, key) -> 
                    key: if (typeOf(val) == Object) processXmlNode(val) else val
                )
            }
        )
---
ns0#trans: processXmlNode(payload.trans)

代码说明 #

1. 递归函数processXmlNode：处理每个JSON对象，拆分属性和子元素
2. partition操作：将对象中@开头的键和普通键分成两组
3. 属性转换：把@开头的键去掉@，并用@前缀标记为XML属性（DataWeave约定）
4. 递归嵌套：对嵌套的JSON对象（如data）重复处理，确保深层的@字段也转为属性

内容的提问来源于stack exchange，提问作者Zak01