[BUG][JAVA] Bug generating spring server: codegenModel is null. Default to UNKNOWN_BASE_TYPE

[fjs018]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
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Description

I am trying to generate a java spring server using 4.0.0-beta2, however generation fails with:

[main] WARN  o.o.codegen.DefaultCodegen - codegenModel is null. Default to UNKNOWN_BASE_TYPE
[main] WARN  o.o.codegen.DefaultCodegen - The following schema has undefined (null) baseType. It could be due to form parameter defined in OpenAPI v2 spec with incorrect consumes. A correct 'consumes' for form parameters should be 'application/x-www-form-urlencoded' or 'multipart/form-data'
[main] WARN  o.o.codegen.DefaultCodegen - schema: class ComposedSchema {
    class Schema {
        title: null
        multipleOf: null

The .java with the generated APIs has the following:
  import org.openapitools.model.UNKNOWN_BASE_TYPE;
  The default ResponseEntity has:
ApiParam(value = "Click on the **Model** below to view the available parameters for this endpoint." ,required=true )  @Valid @RequestBody UNKNOWN_BASE_TYPE UNKNOWN_BASE_TYPE) {

openapi-generator version

4.0.0-beta2 and previous versions.

OpenAPI declaration file content or url

        description: >-
          Click on the **Model** below to view the available parameters for this
          endpoint.
        required: true
        content:
          application/json:
            schema:
              allOf:
                - type: object
                  properties:
                    key:
                      type: string
                      example: S1111...111111
                    alg:
                      type: string
                      example: abc
                    params:
                      type: object
                      oneOf:
                        - $ref: '#/components/schemas/abc_params'
                        - $ref: '#/components/schemas/abb_params'
                        - $ref: '#/components/schemas/aaa_params'
                      example:
                        num: '5521204534320004'
                        expiryDate: 0519
                        sCode: '123'
                      discriminator:
                        propertyName: alg
                        mapping:
                          abc: '#/components/schemas/abc_params'
                          abb: '#/components/schemas/abb_params'
                          aaa: '#/components/schemas/aaa_params'```




##### Command line used for generation

java -jar openapi-generator-cli.jar generate  -i myAPI.yaml -g spring -o spring_server -c  config.json


##### Steps to reproduce

<!-- unambiguous set of steps to reproduce the bug.-->

##### Related issues/PRs

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##### Suggest a fix

<!-- if you can't fix the bug yourself, perhaps you can point to what might be
  causing the problem (line of code or commit), or simply make a suggestion -->

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[fjs018]

I believe that this is all related to the discussion in: #15
@jmini , can you confirm?

[hugotavares]

Hi,
I'm facing this issue as well. Still, I'd like to know whether it exists a workaround or not for it, even though it is by manually setting any configuration parameter on the pom.xml which generates the API.
Thanks in advance.

[Emdee89]

Facing the same issue. Can confirm that the issues does occur once you use oneOf like so:

  /demonstrations:
    post:
      summary: Create Demonstration
      tags: 
        - Demonstrations
      operationId: createDemonstration
      requestBody:
        description: Demonstration details.
        required: true
        content:
          application/json:
            schema:
              oneOf:
                - $ref: '#/components/schemas/demonstrationPayload2'
                - $ref: '#/components/schemas/demonstrationPayload1'
      responses:
        '201':
          description:  created

When we comment oneOf and only mention one entry of $ref, then it works.

[wing328]

As a workaround, what about defining the schema separately (instead of inline)? e.g. https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/test/resources/3_0/allOf.yaml#L43-L52

[Emdee89]

@wing328: I tried that, then it parses the yaml correctly and the source code compiles. However, when you look at the generated code, it does not do what the semantics would imply.

In my experiments, the code generator generates a Java class that looks exactly (of course, except its name) like the Java class that corresponds to the schema mentioned at last under the oneOf declaration. What I'd like to have instead is a Java class that is a super-type of the two mentioned schemas.

[wing328]

I remember the oneOf implementation in Java is still being discussed/worked on.

What I'd like to have instead is a Java class that is a super-type of the two mentioned schemas.

If it's a super-type, what about using allOf instead?

[alfirin]

Same issue here and I don't wat to use the allOf instead.

[dkirrane]

related to
#2845

[jandriescher]

Hey everyone. Was there ever a solution found for this? Facing the same issue with oneOf currently.

[tejarao25]

Facing the same issue with oneOf. Any solution for this issue?

[iekdosha]

I still have this issue with Spring generator. Anything new?

[rossmills3]

Generating code that implements oneOf and allOf requires the use of inheritance in the model. From what I see, the generated code does not use inheritance. However, if I use SwaggerHub site to generate code, inheritance is used to implement oneOf and allOf.

[russ-shmus]

did anyone ever get to the bottom if it? I still see that even latest maven plugin 5.0.0-beta2 fails to generate inheritance code, whereas online generator processes exactly the same yaml correctly. Tried all workarounds found, no luck..

[skchande]

Does "openapi-generator validate -i filename.yml" give you any tips?

Have you tried using Version 3.0?

[frochi42]

Hi,
any progress or workaround here? We are stuck at the same problem, even with version 5.1.1 of theopenapi-generator-maven-plugin.
Thanks a lot!

[Bubo-DBM]

@wing328 Hi, same as @frochi42 I'm getting UNKNOWN_BASE_TYPE with version 5.1.1 with openapi-generator-cli for angular-typescript. Using https://editor.swagger.io/ I'm getting the correct client code.

Below is example yaml code:
`openapi: 3.0.1
info:
title: 'Test Client'
version: 'v1'
description: |
This component store resources and authorizations to MongoDB

paths:
/api/v1/resources/apply-configuration:
post:
operationId: apply-resource
tags:
- 'resources'
summary: apply resource
parameters:
- in: header
name: X-Security
schema:
$ref: '#/components/schemas/header.x-security'
required: true
requestBody:
content:
application/json:
schema:
required: [configuration]
properties:
configuration:
required: [name, type]
properties:
name:
$ref: '#/components/schemas/value.string'
type:
allOf:
- $ref: '#/components/schemas/value.string'
- enum: [security.template/account.v1, security.template/company.v1]
example: security.template/account.v1
description: |
Field | Description
-|-
name | string - the unique name of the configuration
type | string - the configuration type
description: |
Field | Description
-|-
configuration | object - contain configuration propeties
responses:
202:
$ref: '#/components/responses/200-empty'
4XX:
$ref: '#/components/responses/4XX'
5XX:
$ref: '#/components/responses/5XX'
503:
$ref: '#/components/responses/503'

components:
responses:
200-empty:
description: 'Empty success answer'
4XX:
content:
application/json:
schema:
type: object
properties:
code:
type: string
example: 'VAIDATION_ERROR'
correlation:
type: string
example: '146a99c0b0aced9a'
errors:
type: array
items:
type: object
properties:
field:
type: string
example: 'field1'
message:
type: string
example: 'can not be null'
description: 'Client error'
5XX:
content:
application/json:
schema:
$ref: '#/components/schemas/value.error'
description: 'Server error'
503:
content:
application/json:
schema:
$ref: '#/components/schemas/value.error'
description: 'Service unavailable'

schemas:
value.string:
type: string
example: 'any'
description: String value
value.error:
properties:
error:
properties:
code:
type: string
example: 'ERROR'
correlation:
type: string
example: 'any'
description: Error
header.x-security:
type: string
example: '%7B%20%22user%22%3A%20%7B%20%22name%22%3A%20%22cf678c35-806a-47da-b92d-0144e23eb3be%22%2C%20%22alias%22%3A%20%22Lorenzo%20Dodi%22%20%7D%20%7D'
description: 'JSON URL encoded which contain user informatinos as "name" and "alias"'

`

[trackq]

fyi. this also happens for python-fastapi server generation

@router.post(
    "/callthrough",
    responses={
        201: {"model": Call, "description": "Example response"},
    },
    tags=["default"],
    summary="Create a callthrough",
)
async def post_callthrough(
    unknown_base_type: UNKNOWN_BASE_TYPE = Body(None, description=""),
) -> Call:
    """Createa a new callthrough Call"""
    ...

[ghost]

Tried the following in FastApi, but changing to allOf still fails with OpenApi Generator 😢:

def custom_openapi() -> dict[str, dict]:
    openapi_schema = get_openapi(
        title=constants.PROJECT_NAME,
        description=constants.DESCRIPTION,
        version=constants.VERSION,
        routes=app.routes,
    )

    paths = openapi_schema["paths"]
    for path in paths.values():
        for method in path.values():
            if (body := "requestBody") in method:
                schema = method[body]["content"]["application/json"]["schema"]
                if "anyOf" in schema.keys():
                    schema["allOf"] = schema.pop("anyOf")

    app.openapi_schema = openapi_schema
    return app.openapi_schema


app.openapi = custom_openapi

[dbcall2]

This issue was opened three years ago!! The spring code generator is STILL completely broken on polymorphic request/respond bodies. What's causing the delay? Do you guys need people to work on this? Is it internal squabbling about how to "fix" it? I'll gladly volunteer some time to get this fixed as this tech holds promise.

Update: This is not an easy problem to solve... lol. The schema model handling in the spring generator isn't smart enough to traverse the object hierarchy to determine a suitable common parent. And since this is done "pre-java", there's no way to resolve the base class through reflection because it doesn't exist yet. I'm currently looking at ways to solve these issues.

[CoenWarmer]

Any update @dbcall2?

[wing328]

I've merged #12353 to the master which seems to address the inline schema issues in the request bodies. Please pull the latest master to give it a try.