[BUG] [JAVA] regressions introduced by #17622 (lombok)

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• 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

#17622 allows the use of lombok. It works for simple cases but I don't think it is production ready.

There are multiple regressions

• contraints not generated
• JsonProperty gone even if the property name is different than the field name
• javadoc not generated
• incorrect constructors and builders for inheritance
• toString is different (minor)
• x-setter-extra-annotation ignored ( x-extra-field-annotation works)
• probably other missing features : Optional, @Valid...

openapi-generator version

7.3.0-SNAPHOT

OpenAPI declaration file content or url

openapi: 3.0.1
info:
  title: lombok issues
  description: lombok issues
  version: 1.0.0
paths:
  /testLombok:
    get:
      description: test
      responses:
        200:
          description: 'response'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/LombokData'
components:
  schemas:
    ParentData:
      type: object
      properties:
        type:
          type: string
      discriminator:
        propertyName: type
    LombokData:
      allOf:
        - $ref: '#/components/schemas/ParentData'
        - type: object
          properties:
            extra-data:
              description: 'This is an extra-data'
              type: string
              minLength: 10

Here the generated LombokData.java

@lombok.Data
@lombok.NoArgsConstructor
@lombok.AllArgsConstructor
@lombok.Builder
public class LombokData extends ParentData {
  private String extraData;
}

compared to the non lombok version:

  /**
   * This is an extra-data
   * @return extraData
  */
  @Size(min = 10) 
  @Schema(name = "extra-data", description = "This is an extra-data", requiredMode = Schema.RequiredMode.NOT_REQUIRED)
  @JsonProperty("extra-data")
  public String getExtraData() {
    return extraData;
  }

Generation Details

java -jar openapi-generator-cli.jar generate -g spring -i issue_lombok.yaml -p additionalModelTypeAnnotations='@lombok.Data;@lombok.NoArgsConstructor;@lombok.AllArgsConstructor;@lombok.Builder'

Steps to reproduce

Build with 7.3.0-SNAPSHOT with lombok additionalModelTypeAnnotations
java -jar openapi-generator-cli.jar generate -g spring -i issue_lombok.yaml -p additionalModelTypeAnnotations='@lombok.Data;@lombok.NoArgsConstructor;@lombok.AllArgsConstructor;@lombok.Builder'

Related issues/PRs

#17622

Suggest a fix

Fix the different pojo.mustache with

• Constraints on the field

• lombok superBuilder for inheritance

• javadoc on the field

• @JsonProperty on the field (using @Getter(onMethod=@__({@JsonProperty("extra-data")})))

General question: Do we really need a openapi generator that needs lombok to create java classes?
pojo.mustache is already complex.
Configuring lombok is also complex. How to generate for example @Builder(toBuilder=true)?

Lombok is nice when writing code. Here the openapi generator does the job.

The only valid reason I see is the lack of the builder pattern in the current pojo.mustache.
It can be introduced. The generated code can be equivalent or better than a lombok annotated class.

IMHO it will be easier to implements new features without the extra lombok handling (immutability, records, genericity, merging the different java generators...)

Start with the spring generator's pojo.mustache and reproduce the issue using the provided issue_lombok.yaml and generation command. Compare LombokData.java with the non-Lombok output, then verify that constraints, JSON property annotations, Javadoc, inheritance constructors/builders, and extra annotations are preserved.