How to iterator over a JSON Array in Mule 3

Question

Mule 3.8.3 Studio 6.4.4

I am receiving a XML payload that is a collection of customer numbers. I need to end up pulling each number out and sending it to a messaging queue.

Sample Incoming Data:

<request func="">
  <data>
    <transactions time='1539262470'>
      <transaction set='customers' notifyid='WMS_NADC_CUSTOMERS' type='update'>
        <customers>
          <customer id="CIT_1113-11" t="1539257721" y="U" w="WebUser"></customer>
          <customer id="C42998-2" t="1539261561" y="N" w="WebUser"></customer>
          <customer id="C42998" t="1539262040" y="U" w="WebUser"> </customer>
        </customers>
      </transaction>
    </transactions>
  </data>
</request>

After receiving this I use weave to transform into json in an attempt to more easily access the id's.

%dw 1.0
%output application/json
---
{
    customers: payload.request.data.transactions.transaction.customers.*customer map (cust, indexOfCustomer) ->{
        customer: cust.@id as :string
    }
}

The transformed payload now looks like

{
  "customers": [
    {
      "customer": "CIT_1113-11"
    },
    {
      "customer": "C42998-2"
    },
    {
      "customer": "C42998"
    }
  ]
}

At this point, I am trying to loop through the payload. Setting the for each to payload.get('customers') takes me into a jackson.node.ArrayNode.

I haven't been able to figure out how to access each individual object inside the list. Can one of you please tell me how to do that?

I want to end up placing a payload onto a message queue that looks like

{
  "customer": "C42998"
}

score 1 · Accepted Answer · answered Oct 19 '18 at 13:25

The simplest way would be to use a combination of DataWeave to get a Java Iteratable, and a for-each scope. Check out this example (assuming the incoming payload is your XML).

<dw:transform-message doc:name="Transform Message">
            <dw:set-payload><![CDATA[%dw 1.0
%output application/java

%var customers = payload.request.data.transactions.transaction.customers.*customer
---
customers map (customer) ->{
  customer: customer.@id as :string
}]]></dw:set-payload>
</dw:transform-message>
<foreach doc:name="For Each">
    <json:object-to-json-transformer doc:name="Object to JSON"/>
    <logger message="#[payload]" level="INFO" doc:name="Logger"/>
</foreach>

In Mule 3, the for-each won't accept JSON or XML, even if they obviously represent a structure that could be iterated over (like a JSON array, for example). This is why we need %output application/java in the DataWeave transformer. Later, within the for-each scope, we can transform this back to JSON. In your case, just replace the logger with your queue connector to send the messages where needed.

That worked wonderfully. This was exactly what I needed. Thank you — Leonard White, Oct 19 '18 at 16:26

How to iterator over a JSON Array in Mule 3

1 Answers1