Mule4中ForEach中的聚合

Question

我想聚合For Each的每次迭代的响应。在每次迭代中，我都会获得Json数据，并希望将这些Json数据聚合到Json Array/List中。请让我知道如何通过在转换中使用数据编织或任何其他方式来做到这一点？

下面是我在For Each的每次迭代中获得的示例Json数据。

1st iteration:
{
    "accountId": "12345",
    "accountNumber": "999",
    "accountTitle": "ABC"
}

2nd iteration:
{
    "accountId": "98765",
    "accountNumber": "888",
    "accountTitle": "XYZ"
}

I want final aggregated output as below.  
{
  accountList: [
    {
        "accountId": "12345",
        "accountNumber": "999",
        "accountTitle": "ABC"
    },
    {
        "accountId": "98765",
        "accountNumber": "888",
        "accountTitle": "XYZ"
    }
  ]
}

Answer 1

您可以遵循如下内容

<!-- Define blank arraylist for aggregation -->
        <dw:transform-message doc:name="Transform Message">
            <dw:set-variable variableName="result"><![CDATA[%dw 1.0
%output application/java
---
[]]]></dw:set-variable>
        </dw:transform-message>
        <foreach doc:name="For Each">
            <!-- generate response using flow logic and add following step for updating result array -->
            <dw:transform-message doc:name="Transform Message">
                <dw:set-variable variableName="result"><![CDATA[%dw 1.0
%output application/java
---
flowVars.result ++ [payload]]]></dw:set-variable>
            </dw:transform-message>
        </foreach>
        <!-- Transform aggregated result to any format. I used JSON -->
        <dw:transform-message doc:name="Transform Message">
            <dw:set-payload><![CDATA[%dw 1.0
%output application/json
---
accountList : flowVars.result]]></dw:set-payload>
        </dw:transform-message>

我使用了Mule 3.x语法。对于Mule4，您可以使用attribute代替variable来存储记录。除了将Dataweave语言版本从1.0更改为2.0外，Dataweave语法将保持不变。

希望这能有所帮助。