[BUG] [Java] [spring] Properties that are both required and nullable are marked NotNull

[mdaul-tgtg]

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

When a nullable property is required, the generated class has a non-nullable field and getter.

openapi-generator version

7.24.0

OpenAPI declaration file content or url

This is an example spec that I used to reproduce:

{
  "openapi": "3.1.0",
  "info": {
    "title": "Reproduce",
    "version": "1.0.0"
  },
  "paths": {
    "/thing": {
      "get": {
        "operationId": "getThing",
        "responses": {
          "200": {
            "description": "ok",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Thing"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "Thing": {
        "type": "object",
        "required": [
          "name",
          "description"
        ],
        "properties": {
          "name": {
            "anyOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ]
          },
          "description": {
            "anyOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ]
          }
        }
      }
    }
  }
}

Generation Details

Java 17

JAR=openapi-generator/modules/openapi-generator-cli/target/openapi-generator-cli.jar

"$JAVA_HOME/bin/java" -jar "$JAR" generate \
  -i spec.json \
  -g spring \
  -o out \
  --additional-properties=useJspecify=true,hideGenerationTimestamp=true,openApiNullable=false

Steps to reproduce

Run the generator tool on the spec above with the provided options. Observe that the resulting class does not have the right nullability marks:

public class Thing {

  private String name = null; // field should be @Nullable

  /**
   * Get name
   * @return name
   */
  @NotNull // wrong annotation, should be @Nullable
  @Schema(name = "name", requiredMode = Schema.RequiredMode.REQUIRED)
  @JsonProperty("name")
  public String getName() {
    return name;
  }

  @JsonProperty("name")
  public void setName(String name) { // parameter should be @Nullable
    this.name = name;
  }

Related issues/PRs

#23866
#20827

[jpfinne]

@mdaul-tgtg this is not a issue with the anyof in 3.1. I reproduce the issue in 3.0.3:

---
openapi: 3.0.3
info:
  title: Reproduce
  version: 1.0.0
paths:
  "/thing":
    get:
      operationId: getThing
      responses:
        '200':
          description: ok
          content:
            application/json:
              schema:
                "$ref": "#/components/schemas/Thing"
components:
  schemas:
    Thing:
      type: object
      required:
        - name
        - description
      properties:
        name:
          type: string
          nullable: true
        description:
          type: string
          nullable: true

I get these results:

Generator	useJspecify	openApiNullable	setter	chain	getter
Spring	true	false	void setName(String name)	Thing name(String name)	@NotNull String getName()
Spring	false	false	void setName(String name)	Thing name(String name)	@NotNull String getName()
Spring	true	true	void setName(JsonNullable<String> name)	Thing name(String name)	JsonNullable<String> getName()
Spring	false	true	void setName(JsonNullable<String> name)	Thing name(String name)	JsonNullable<String> getName()
restClient	true	false	void setName(String name)	Thing name(String name)	String getName()
restClient	false	false	void setName(@jakarta.annotation.Nullable String name)	Thing name(@jakarta.annotation.Nullable String name)	@jakarta.annotation.Nullable String getName()

Missing Spring + useOptional and restclient + openanApiNullable

It means that:

• java + jspecify + openapiNullable=false, there is a regression. I'll have a look, I've worked on jspecify quite a lot.
• Spring, the bug already existed. To be checked if it existed before the introduction of jspecify

[mdaul-tgtg]

@jpfinne I added spring in the title since it's the one I am interested in, and where the bug has always existed.

this is not a issue with the anyof in 3.1

But this is what I used to reproduce. Didn't you get the same results as I did with my spec?

[jpfinne]

@mdaul-tgtg I think we have the same issue using 3.0.x and 3.1.x. It means that the bug is not in the new normalizer rules.

Quick solution. use these templates for spring
beanValidation.mustache

{{#required}}{{^useJspecify}}{{^isReadOnly}}@NotNull {{/isReadOnly}}{{/useJspecify}}{{/required}}{{#isContainer}}{{^isPrimitiveType}}{{^isEnum}}@Valid {{/isEnum}}{{/isPrimitiveType}}{{/isContainer}}{{^isContainer}}{{^isPrimitiveType}}@Valid {{/isPrimitiveType}}{{/isContainer}}{{^openApiNullable}}{{>beanValidationCore}}{{/openApiNullable}}{{#openApiNullable}}{{^useOptional}}{{>beanValidationCore}}{{/useOptional}}{{/openApiNullable}}{{#useOptional}}{{#openApiNullable}}{{#isContainer}}{{^required}}{{>beanValidationCore}}{{/required}}{{/isContainer}}{{/openApiNullable}}{{#openApiNullable}}{{#required}}{{>beanValidationCore}}{{/required}}{{/openApiNullable}}{{/useOptional}}

meaning that @NotNull is not added for jspecify.

nullableAnnotation_jspecify.mustache

{{#useJspecify}}{{#lambda.jSpecifyNullable}}{{#required}}{{#isNullable}}{{^openApiNullable}}@Nullable {{/openApiNullable}}{{/isNullable}}{{/required}}{{^required}}{{^useOptional}}{{#openApiNullable}}{{^isNullable}}@Nullable {{/isNullable}}{{/openApiNullable}}{{^openApiNullable}}@Nullable {{/openApiNullable}}{{/useOptional}}{{/required}}{{/lambda.jSpecifyNullable}}{{/useJspecify}}

meaning that required && isNullable && && !openapiNullable -> @Nullable added

There was no unit test for this use case, that why I missed it in the implementation of JSpecify.

[mdaul-tgtg]

Thank you! For now, I'm just using additionalModelTypeAnnotations to add @NullUnmarked on the generated classes and ignore the issues until this is fixed.

[jpfinne]

@mdaul-tgtg Then you get something like the class below. How does it solve your issue? Don't you want @Nullable annotations?

@NullMarked
public class Thing {

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }
}

[mdaul-tgtg]

@jpfinne I do! I added NullUnmarked which means unspecified nullness - so it is not treated as non-nullable by the rest of the code. But this is a temporary workaround, in the end, I want the right annotations and nullability handling. Sorry if it was confusing.