I can do adhoc mapping of the response using tExtractJSONFields.
I've imported a sample JSON response into a reusable File JSON metadata schema. I have no idea how to map either "string" or "body" response to a pre-defined metadata JSON schema. Is this even possible? I believe it's doable for XML using tXMLMap but nothing exists for JSON.
You will need to look at the tWriteJSONField component. Take a look here: https://help.talend.com/reader/KxVIhxtXBBFymmkkWJ~O4Q/50PMKM8mz4A5fAL~FQcLHw
Try Talend Cloud free for 30 days.
Introduction to Talend Open Studio for Data Integration.
Practical steps to developing your data integration strategy.
Create systems and workflow to manage clean data ingestion and data transformation.