如何在DataWeave 2.0（Mule 4）中将XML转为单行格式？

需求说明 #

需将带有换行、空格、制表符的结构化XML，转换为无任何空白字符的单行XML，并包裹在{body: ...}的JSON结构中。

输入示例 #

<tns:ResponseMessage xmlns:n1="urn:sap-com:document:sap:rfc:functions" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/">

 <tns:Header>
   <tns:Verb>reply</tns:Verb>
   <tns:Noun>Compressed</tns:Noun>
   <tns:User/>

   <Signature xmlns="">
     <SignedInfo>
       <CanonicalizationMethod Algorithm=""/>
       <SignatureMethod Algorithm=""/>
     </SignedInfo>

     <SignatureValue>XW8UqTTcR==</SignatureValue>

     <KeyInfo>
       <X509Data>
         <X509IssuerSerial>
           <X509IssuerName></X509IssuerName>
           <X509SerialNumber>1448033456</X509SerialNumber>
         </X509IssuerSerial>
         <X509SubjectName></X509SubjectName>
         <X509Certificate>MIIF8z</X509Certificate>
       </X509Data>
     </KeyInfo>
   </Signature>
 </tns:Header>

 <tns:Reply>
   <tns:Result>OK</tns:Result>
   <tns:ID idAuthority="" idType="" kind="" objectType=""/>
   <tns:operationId>0</tns:operationId>
 </tns:Reply>

 <tns:Payload>
   <tns:OperationSet>
     <tns:enforceMsgSequence>false</tns:enforceMsgSequence>
   </tns:OperationSet>
   <tns:Compressed>QlpoORdyRThQkAA=</tns:Compressed>
 </tns:Payload>
</tns:ResponseMessage>

预期输出 #

{body:<tns:ResponseMessage xmlns:n1="urn:sap-com:document:sap:rfc:functions" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"><tns:Header><tns:Verb>reply</tns:Verb><tns:Noun>Compressed</tns:Noun><tns:User/><Signature xmlns=""><SignedInfo><CanonicalizationMethod Algorithm=""/><SignatureMethod Algorithm=""/></SignedInfo><SignatureValue>XW8UqTTcR==</SignatureValue><KeyInfo><X509Data><X509IssuerSerial><X509IssuerName></X509IssuerName><X509SerialNumber>1448033456</X509SerialNumber></X509IssuerSerial><X509SubjectName></X509SubjectName><X509Certificate>MIIF8z</X509Certificate></X509Data></KeyInfo></Signature></tns:Header><tns:Reply><tns:Result>OK</tns:Result><tns:ID idAuthority="" idType="" kind="" objectType=""/><tns:operationId>0</tns:operationId></tns:Reply><tns:Payload><tns:OperationSet><tns:enforceMsgSequence>false</tns:enforceMsgSequence></tns:OperationSet><tns:Compressed>QlpoORdyRThQkAA=</tns:Compressed></tns:Payload></tns:ResponseMessage>}

解决方案：DataWeave 2.0 转换脚本 #

%dw 2.0
output application/json
var xmlAsString = write(payload, "application/xml", {indent: false})
var strippedXml = xmlAsString replace /\s+/ with ""
---
{
    body: strippedXml
}

脚本说明 #

1. 序列化XML为无格式字符串：write(payload, "application/xml", {indent: false}) 将输入的XML对象转为字符串，通过indent: false禁用自动格式化的缩进和换行。
2. 清除所有空白字符：xmlAsString replace /\s+/ with "" 用正则匹配所有连续空白（空格、换行、制表符），替换为空字符串，彻底移除所有无关空白。
3. 生成目标结构：将处理后的单行XML放入body字段，输出符合要求的JSON结构。

特殊场景处理 #

如果XML文本节点中存在需要保留的空格（如<desc>hello world</desc>），需修改正则表达式，仅清除标签之间的空白：

var strippedXml = xmlAsString replace /(?<=>)\s+(?=<)/ with ""

内容的提问来源于stack exchange，提问作者Bianca Ilas