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

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?
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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

@mdaul-tgtg

@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

@jpfinne

@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?

@mdaul-tgtg

@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.

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

@mdaul-tgtg

@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;
  }
}

@jpfinne

@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.

@jpfinne

Hi, I'd like to work on this fix. @jpfinne .. are you planning to submit a PR for the template changes you outlined? If not, I'd like to take a shot at it.

@itsmib

@itsmib I have a draft PR #24711 .
I still need to check what to do with the ‘@NotNull’ annotation. See the regression found by Cubic.
I think it is needed for Hibernate validation on required and non nullable field.
For required and nullable I can introduce an annotation like ’@JsonNullableRequired’

@itsmib

@itsmib @mdaul-tgtg can your review #24711?

And if ok, please approve

@itsmib using your sample, the generated code becomes:

  private @Nullable String name = null;
  
  @Schema(name = "name", requiredMode = Schema.RequiredMode.REQUIRED)
  @JsonProperty("name")
  public @Nullable String getName() {
    return name;
  }
  public Thing name(@Nullable String name) {
    this.name = name;
    return this;
  }
  @JsonProperty("name")
  public void setName(@Nullable String name) {
    this.name = name;
  }

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[BUG] [Java] [spring] Properties that are both required and nullable are marked NotNull #24686

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[BUG] [Java] [spring] Properties that are both required and nullable are marked NotNull #24686

Description

Bug Report Checklist

Description

openapi-generator version

OpenAPI declaration file content or url

Generation Details

Steps to reproduce

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jpfinne commented on Aug 12, 2026

mdaul-tgtg commented on Aug 12, 2026

jpfinne commented on Aug 12, 2026

mdaul-tgtg commented on Aug 12, 2026

jpfinne commented on Aug 12, 2026

mdaul-tgtg commented on Aug 12, 2026

itsmib commented on Aug 15, 2026

jpfinne commented on Aug 15, 2026

jpfinne commented on Aug 15, 2026

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