Mule Dataweave：使用 when 和 Map

Question

我需要根据以下输入的类别检索 AmountRequired 并列出所有重复的元素。

<root>
    <Unspecified>
        <Category>T03</Category>
        <AmountRequired>993</AmountRequired>
        <ExcessAmount>250</ExcessAmount>
        <Currency>GBP</Currency>
        <ExchangeRate>1</ExchangeRate>
    </Unspecified>
    <Unspecified>
        <Category>T03</Category>
        <AmountRequired>9903</AmountRequired>
        <ExcessAmount>250</ExcessAmount>
        <Currency>GBP</Currency>
        <ExchangeRate>1</ExchangeRate>
    </Unspecified>
    <Unspecified>
        <Category>P02</Category>
        <AmountRequired>992</AmountRequired>
        <Currency>GBP</Currency>
        <ExchangeRate>1</ExchangeRate>
    </Unspecified>
    <Unspecified>
        <Category>A29</Category>
        <AmountRequired>929</AmountRequired>
        <Currency>GBP</Currency>
        <ExchangeRate>1</ExchangeRate>
    </Unspecified>
</root>

我想要输出如下。当 T03 有 2 个标签时，它应该显示如下两个金额。此外，如果类别不存在，则它不存在，例如 P05，如果我们对其进行转换，则它会错误地指出 P05 不存在，那么有没有办法克服错误，即使输入 xml 不包含 P05 类别？

<amountRequired>
        <amount>929</amount>
        <currency>GBP</currency>
        <exchangeRate>1</exchangeRate>
        <amountInSystemCurrency>550</amountInSystemCurrency>
    </amountRequired>
<amountRequired>
    <amount>993</amount>
    <currency></currency>
    <exchangeRate></exchangeRate>
    <amountInSystemCurrency></amountInSystemCurrency>
</amountRequired>
<amountRequired>
    <amount>9903</amount>
    <currency></currency>
    <exchangeRate></exchangeRate>
    <amountInSystemCurrency></amountInSystemCurrency>
</amountRequired>
<amountRequired>
        <amount>992</amount>
        <currency></currency>
        <exchangeRate></exchangeRate>
        <amountInSystemCurrency></amountInSystemCurrency>
    </amountRequired>

非常感谢对此的任何帮助

Answer 1

你可以使用下面的代码 -

%dw 1.0
%output application/xml
---
using (T03=payload.root.*Unspecified filter ($.Category == 'T03')){
    //
    amountRequired:{  
    amount:T03.AmountRequired[0] default 0,
    currency:"",
    exchangeRate:"",
    amountInSystemCurrency:""
} 
}

它使用一个变量T03 来保存从原始负载中过滤出来的T03 类别项。 amount: T03.AmountRequired[0] default 0 存在时将从 T03 输出数量，否则默认为 0。

在这个答案的评论中，您似乎已经更改了要求:)。无论如何，编辑此答案以适应以下评论“
我已经编辑了问题，希望它有意义。我要输出所有的标签（注意：T03重复了，要输出两个） – Neil24 13 mins ago"

%dw 1.0
%output application/xml
---
{
    root : { (payload.root.*Unspecified map 
        amountRequired: {
            amount:$.AmountRequired unless $.Category != 'T03' otherwise 0,
            currency:"",
            exchangeRate:"",
            amountInSystemCurrency:""
        }
    )}
}

这是非常直接的转换，金额字段为 0，除非当前类别为 T03。在最初的问题中你提到只有当它是 T03 类别时你才需要金额所以除非..否则检查，如果你想要每个类别的金额，只需将其删除。

希望对您有所帮助！

Mule Dataweave：使用 when 和 Map

Mule Dataweave: using when and Map

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