How to transform json payload in multipart/form-data request

[diogoalfarelos]

Hello

Currently i'm trying to implement a proxy where i receive multipart/form-data request with two form-datas

1\ a JSON payload

2\ a binary payload (file)

My objective is to leave the binary payload untouched and foward it normally to the backend service but i need to transform the JSON payload to a specific XML format.

I've seen some java libraries to handle binary payloads but since i don't want to change this part, is there any way i can approach this by just using the normal policies provided by Apigee Edge?

Thanks!