使用XSLT 1.0为XML添加父节点解决文档良构报错问题

标准XML语法强制要求单个文档有且仅有一个顶层根元素，当前收到的内容在XML声明后并列存在<SARIETransferRq>、<Signature>两个同级顶层节点，不符合良构要求，传入XSLT处理器时就会触发根元素之后的文档标记必须符合良构规范的报错。只要给所有顶层节点套一层统一的父根节点就能彻底解决问题。

最稳定、兼容性最好的方式是在将内容传入XSLT处理器前做一层轻量预处理，不需要改动原有业务节点的任何内容、结构、缩进，实现逻辑非常简单：

• 第一步：提取原始内容开头的XML声明段：<?xml version="1.0" encoding="UTF-8" ?>
• 第二步：在XML声明后拼接自定义根节点的起始标签<SampleRoot>
• 第三步：原封不动拼接XML声明之后的所有原始业务内容
• 第四步：在内容末尾拼接根节点的闭合标签</SampleRoot>，就能得到符合要求的良构XML。

如果担心纯字符串拼接的容错问题，也可以用支持XML片段解析的工具读取原始内容：先手动创建<SampleRoot>作为根节点，再把解析得到的两个原始顶层节点（SARIETransferRq、Signature）作为子节点挂到根节点下，最后序列化输出即可，全程不会修改原始业务字段的任何值。

不推荐依赖XSLT引擎的非标准配置直接解析多根内容，不同版本、不同厂商的XSLT处理器对非良构XML的兼容逻辑差异很大，生产环境容易出现偶发解析失败的问题。

<?xml version="1.0" encoding="UTF-8" ?>
<SARIETransferRq>
    <SARIETransferRqHeader>
        <CorporateID>Sample123</CorporateID>
        <CorpReferenceNumber>Sample123</CorpReferenceNumber>
    </SARIETransferRqHeader>
    <SARIETransferRqBody>
        <AccountNumber>0000111111111222222</AccountNumber>
        <DebitCurrency>SAR</DebitCurrency>
        <TransferAmount>12</TransferAmount>
        <TransferCurrency>SAR</TransferCurrency>
        <BeneficiaryName>SAMPLE NAME</BeneficiaryName>
        <BeneficiaryAccountNumber>Sample1231111111</BeneficiaryAccountNumber>
        <BeneficiaryAddress1>733r</BeneficiaryAddress1>
        <BeneficiaryAddress2>6Sample123y</BeneficiaryAddress2>
        <BeneficiaryAddress3>1Sample123ver</BeneficiaryAddress3>
        <BankBIC>AAAAAA</BankBIC>
        <PaymentDate>2021-02-24</PaymentDate>
        <Instructions1>qewerr</Instructions1>
        <Instructions2>luaba</Instructions2>
        <Instructions3>fadjiugu</Instructions3>
        <Instructions4>rifdij</Instructions4>
        <Description>sample description for service fee</Description>
        <AMLPurposeCode>BB</AMLPurposeCode>
    </SARIETransferRqBody>
</SARIETransferRq>
<Signature>
    <SignatureValue>sample</SignatureValue>
</Signature>

<?xml version="1.0" encoding="UTF-8" ?>
<SampleRoot>
<SARIETransferRq>
    <SARIETransferRqHeader>
        <CorporateID>Sample123</CorporateID>
        <CorpReferenceNumber>Sample123</CorpReferenceNumber>
    </SARIETransferRqHeader>
    <SARIETransferRqBody>
        <AccountNumber>0000111111111222222</AccountNumber>
        <DebitCurrency>SAR</DebitCurrency>
        <TransferAmount>12</TransferAmount>
        <TransferCurrency>SAR</TransferCurrency>
        <BeneficiaryName>SAMPLE NAME</BeneficiaryName>
        <BeneficiaryAccountNumber>Sample1231111111</BeneficiaryAccountNumber>
        <BeneficiaryAddress1>733r</BeneficiaryAddress1>
        <BeneficiaryAddress2>6Sample123y</BeneficiaryAddress2>
        <BeneficiaryAddress3>1Sample123ver</BeneficiaryAddress3>
        <BankBIC>AAAAAA</BankBIC>
        <PaymentDate>2021-02-24</PaymentDate>
        <Instructions1>qewerr</Instructions1>
        <Instructions2>luaba</Instructions2>
        <Instructions3>fadjiugu</Instructions3>
        <Instructions4>rifdij</Instructions4>
        <Description>sample description for service fee</Description>
        <AMLPurposeCode>BB</AMLPurposeCode>
    </SARIETransferRqBody>
</SARIETransferRq>
<Signature>
    <SignatureValue>sample</SignatureValue>
</Signature>
</SampleRoot>

内容的提问来源于stack exchange，提问作者Varaprasad Bolisetty