Design pattern to editor of templates in Spring

I have a service in Spring that reads a template written/edited by user and with fields and entities existing in template (edited by user) are return the results of this template. Example: , in this case user are a entity and name is a field written by user, follow example, the question is what best design pattern to this service ? for the better organized.

http://ift.tt/2qYgoGc

Note: the entity represent a endpoint, this service is a big client of an API