[JAVA] Empty array not getting picked as default for the defined model in Open API AKA Swagger generated code

Description

While designing the API, I am defining a UserGeo model that contains two fields - domain (string array) and country (string array).

An empty List [] should be used in the request body if no value is provided for the domain.
But on defining the default property as [] the generates Spring code does not assign empty ArrayList<> aka [].

Swagger-codegen - Same as that on swagger.io

Swagger declaration file content or url

Attaching the code samples:

Swagger Definition:

definitions:
  UserGeo:
    type: "object"
    properties:
      country:
        type: "array"
        items:
          type: "string"
      domain:
        type: "array"
        items:
          type: "string"
        default: []

This does not default the domain value to an empty list, check this generated Spring/Java code:

.
.
public class Classification   {
  @JsonProperty("country")
  @Valid
  private List<String> country = null;

  @JsonProperty("domain")
  @Valid
  private List<String> domain = null;
.
.

Whereas when I define the domain field as required without even defining it with default, the generated code assigns an empty list as default for the domain.

definitions:
  UserGeo:
    type: "object"
    required:
      - "domain"
    properties:
      country:
        type: "array"
        items:
          type: "string"
      domain:
        type: "array"
        items:
          type: "string"

And as mentioned the generated code has an empty list assigned for the domain.

public class UserGeo   {
  @JsonProperty("country")
  @Valid
  private List<String> country = null;

  @JsonProperty("domain")
  @Valid
  private List<String> domain = new ArrayList<String>();

Command line used for generation

Steps to reproduce

Go to https://editor.swagger.io/ , paste the YAML in definitions and generate server code -> spring

Suggest a fix/enhancement

If a field is required in the model (even of type array), the generated code should not automatically assign an empty array when the field is missing.
And defaults should only be used when they are specifically asked to.

Start with the supplied OpenAPI definition and compare the generated Spring/Java model for an array with default: [] against one where the array is required. Clarify the intended distinction between explicit defaults and required fields, then verify that generated model initialization follows that decision.