Create Big Json Body Request Dynamically

I’m kind of a newbie with Gatling

What is the best way to create a json Body of the form that follows (only id and number should be unique per body ),
this could contain around 1000 entries
It is easy to generate this and just use the body directly from a file,
but i am looking for a more concise way

  {"id":"77c1603c-305f-4584-9b58-da6849a6b067","number":"15555854256","message":"In congue. Etiam justo. Etiam pretium iaculis justo."...,