[FIXED] Normalize response body in spring boot

Issue

I do have some entity class (code without annotations for simplified example)

class User {
   public String id;
   public String name;
}

Now I want to output this via an API, but I want to structure my response in a special format, like

{
  "data": {
            "id": 1,
            "name": "mars3142"
          }, // user object or another entity or list...
  "meta": ...,
  "error": ...
}

The meta and/or error data should only be visible in special situations (like RuntimeExceptions). Where is the best place to transform my entity results into the normalized response? Do I need to write a filter for that? Does anybody has a sample code for that?

Solution

I used the solution from https://stackoverflow.com/a/72355056/708157 and transformed it a little bit.

Now my classes are that way

public class BaseResponse<T> {
  boolean success;
  T data;
  Error error;
}

public class Error {
  ...
}

And every api response is now ResponseEntity<BaseResponse<XYZ>>. This way, I can setup my default structure and my classes are lose coupled, because I can use every class for T within my BaseResponse.

Answered By - mars3142
Answer Checked By - Terry (JavaFixing Volunteer)