Generating random numbers in mule dataweave - mule

Question

I have to concatenate randomly generated number with the field from request in dataweave.
NUMBR: "AA" ++ $.Load.Reference.*Reference ++ RandomNumber
How to achieve this in Mule Dataweave

Answer 1

Not sure what you can do in Datawevae to do this, but you can you set a Random number in a flowVariable and invoke it from your Dataweave script like so:
<set-variable variableName="random"
value="#[new java.util.Random().nextInt(100)]" doc:name="Variable" />
<dw:transform-message doc:name="Transform Message">
<dw:input-variable doc:sample="unknown.dwl" variableName="random" />
<dw:set-payload>
<![CDATA[%dw 1.0
%output application/dw
---
{
"data": ("22" as :number + flowVars.random)
} ]]>
</dw:set-payload>
</dw:transform-message>

Answer 2

You can also use Expression Component to assign it to Payload or variables and then concatenate
<flow name="random-numbersFlow">
<http:listener config-ref="HTTP_Listener_Configuration" path="/random" allowedMethods="GET" doc:name="HTTP"/>
<expression-component doc:name="Expression"><![CDATA[payload = new java.util.Random().nextInt(100)]]></expression-component>
<dw:transform-message doc:name="Transform Message">
<dw:set-payload><![CDATA[%dw 1.0
%output application/java
---
{
data: payload
}]]></dw:set-payload>
</dw:transform-message>
<logger message="#[payload]" level="INFO" doc:name="Logger"/>
</flow>

Answer 3

You can't do this in pure DataWeave but you could use two methods to generate the number elsewhere in the application:
You could call a global MEL function from DataWeave: https://docs.mulesoft.com/mule-user-guide/v/3.7/dataweave-reference-documentation#global-mel-functions
You could call a flow that returns the value: https://docs.mulesoft.com/mule-user-guide/v/3.7/dataweave-reference-documentation#expressions-that-call-external-flows

Answer 4

Just set a random value generated by Java into a Flow Variable
<set-variable variableName="Random_Variable" value="#[java.util.Random().nextInt(10)]" doc:name="Random Variable"/>
Then Use that Flow Variable in your Dataweave Transform.
<dw:transform-message doc:name="Transform Message" metadata:id="8098b24c-30c1-4e9e-a3ce-9e8aaaec7bd1">
<dw:input-variable mimeType="application/java" variableName="Random_Variable"/>
<dw:set-payload><![CDATA[%dw 2.0
%output application/json
---
{
NUMBR: "AA" ++ $.Load.Reference.*Reference ++ flowVars.Random_Variable
}]]></dw:set-payload>
</dw:transform-message>

Answer 5

In Mule 4 Dataweave 2 function random()
Returns a pseudo-random number greater than or equal to 0.0 and less than 1.0
MULE 4 DOC:
https://docs.mulesoft.com/dataweave/2.3/dw-core-functions-random
Example:
%dw 2.0
output application/json
{ price: random() * 1000 }