How I can encode a payload (application/pdf) into Base64 using Mule4 and Dataweave 2.0?

Question

I am new to Mule4 and Dataweave 2.0 and I am having a hard time trying to convert an HTTP Request response into a Base64 value. In a few steps here is what I am doing:

Send a request to an API and outputting the response as "application/pdf"
Converting the payload to an string
"Encoding" the payload to Base64
Adding the result to an array

Here is the XML involved on the actions before:

<foreach doc:name="For Each Documents in FactIntake" doc:id="6ee1729e-0280-41e6-bc29-039ad404d74d" collection="vars.factIntake.documents">
    <set-variable value="#[vars.factIntake.documents[0].documentId]" doc:name="Set documentId" doc:id="c28e1d72-bb82-43af-b340-d91b5cbc428e" variableName="docId"/>
    <http:request method="GET" doc:name="GetDocumentMetadata" doc:id="87006616-e519-4f0f-b5e2-be33c6cf5dae" config-ref="HTTP_Request_DocManagement" path="documents/{documentId}" outputMimeType="application/pdf">
        <http:uri-params><![CDATA[#[output application/java
---
{
    documentId : vars.factIntake.documents[0].documentId
}]]]></http:uri-params>
        <http:response-validator>
            <http:success-status-code-validator values="200, 404"/>
        </http:response-validator>
    </http:request>
    <choice doc:name="Condition" doc:id="76c0dc6f-3d9c-452f-960d-6bd8a0039ebc">
        <when expression="#[attributes.statusCode == 200]">
            <ee:transform doc:name="Transform Message" doc:id="ad2a1dd7-0973-4854-b44c-bdfe8eb54778">
                <ee:message>
                    <ee:set-payload><![CDATA[%dw 2.0
output application/java
---

write(payload, "text/plain")]]></ee:set-payload>
                </ee:message>
                <ee:variables>
                    <ee:set-variable variableName="documentsArray"><![CDATA[%dw 2.0
output application/java
---
vars.documentsArray + vars.document]]></ee:set-variable>
                </ee:variables>
            </ee:transform>
            <ee:transform doc:name="Transform Message" doc:id="9ef64824-ffc1-4a56-b97c-d57cc37800a5">
                <ee:message>
                    <ee:set-payload><![CDATA[%dw 2.0
import * from dw::core::Binaries
output application/java
---
vars.documentsArray + toBase64(payload)]]></ee:set-payload>
                </ee:message>
            </ee:transform>
        </when>
        <otherwise>
            <flow-ref doc:name="Document Not Found Logging" doc:id="0d6b7df4-fde1-4d77-9257-2ffe1e9f5468" name="IntegrationFabricLogsFlow"/>
        </otherwise>
    </choice>
</foreach>

The problem? The values added to documentsArray are NULL. What I am missing here? I am running out of ideas and Google/Internet hasn't been helpful on this topic.

Any help/ideas?

Satheesh Kumar Satheesh Kumar · Accepted Answer · 2019-05-29T02:25:38

seems like your payload is a java object and not binary, so convert it to binary before converting to base 64

%dw 2.0
import * from dw::core::Binaries    
var binaryPayload = payload as Binary
output application/java
---
    vars.documentsArray + toBase64(binaryPayload)

How I can encode a payload (application/pdf) into Base64 using Mule4 and Dataweave 2.0?

1 Answers