[Apache Nifi] - Convert Avro or JSON to XML generic

[#1]

Hi folks,

I want to transform the result of the QueryCassandra Processor (which is in Avro or Json) in to xml format.

Is there any way to do this, it would be best when there is a generic way, so I wouldnt need to set a explicit shema or sth. for different querys. Something like this just into the opposite direction

https://community.hortonworks.com/articles/29474/nifi-converting-xml-to-json.html

I hope someone can help me.

Thx

[#2]

Maybe this is already a solution

https://community.hortonworks.com/questions/101298/apache-nifi-json-to-xml-or-xml-translation.html

But could someone explain me how to set up this exactly with input json string from flowfile and output xml should be than again a flowfile.