[BUG] [JAVA] [Spring] Minimum/maximum parameters are written in scientific notation in JSR-301 annotations

[thegli]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

With model 'spring' and OAS 2 spec, the values in the generated JSR-301 annotations for "minimum" and "maximum" parameters for the items of an array are written in scientific notation.
So instead of expected:

  @Valid
  private Set<@Min(100) @Max(200)Integer> numberlist = new LinkedHashSet<>();

the following is generated, which is not valid Java code:

  @Valid
  private Set<@Min(1E+2) @Max(2E+2)Integer> numberlist = new LinkedHashSet<>();

This problem does NOT occur:

• if the (semantically) same spec is in OAS 3 format
• for properties that are not items of an array (see "magicnumber" in the example)

openapi-generator version

Tried with 7.17.0, but also with 7.2.0 and many in-between releases. It does not look like a regression to me but more like a "never worked as expected" situation (?)

OpenAPI declaration file content or url

OAS 2 spec - this one causes the scientific notation output for the "numberlist" array property:

swagger: '2.0'
info:
  title: MinMax Bug Sample
  version: '1'

paths:
  /minmaxbug:
    post:
      operationId: demonstrateMinMaxBug
      produces:
        - application/json
      consumes:
        - application/json
      parameters:
        - in: body
          name: request
          required: true
          schema:
            $ref: '#/definitions/Foo'
      responses:
        '201':
          description: 'List of numbers created'
          schema:
            $ref: '#/definitions/Foo'

definitions:
  Foo:
    type: object
    required:
      - numberlist
      - magicnumber
    properties:
      numberlist:
        type: array
        minItems: 1
        maxItems: 10
        uniqueItems: true
        items:
          type: integer
          format: int32
          minimum: 100
          maximum: 200
          example: 123
      magicnumber:
        type: integer
        format: in32
        minimum: 300
        maximum: 400
        example: 345

OAS 3 spec - this one generates proper Java code for "numberlist":

openapi: 3.0.1
info:
  title: MinMax Bug Sample
  version: "1"

paths:
  /minmaxbug:
    post:
      operationId: demonstrateMinMaxBug
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Foo'
        required: true
      responses:
        "201":
          description: List of numbers created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Foo'

components:
  schemas:
    Foo:
      required:
      - numberlist
      type: object
      properties:
        numberlist:
          minItems: 1
          maxItems: 10
          uniqueItems: true
          type: array
          items:
            type: integer
            format: int32
            minimum: 100
            maximum: 200
            example: 123
        magicnumber:
          type: integer
          format: in32
          minimum: 300
          maximum: 400
          example: 345

Generation Details

Used the latest release of the CLI generator, with minimal parameters (see next section).

Steps to reproduce

java -jar openapi-generator-cli-7.17.0.jar generate -i ./oas2.yaml -o ./output/oas2/ 
-g spring -p useSpringBoot3=true

Related issues/PRs

A similar issue where scientific notation is also unexpectedly generated was posted just recently: #22341

Suggest a fix

No fix at hand - I looked at *beanValidationCore.mustache - but it could be a type-conversion-chain issue like "string -> large number object such as BigDecimal -> to-string-method-that-prefers-scientific-notation".