[BUG][Java][Native] Lack of AnyOf class

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• 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?
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Description

When I'm trying to build code generated from the OpenApi spec file with "anyOf", it fails because of the lack of "AnyOfAWSPreferenceAzurePreference" class.

openapi-generator version

5.1.1

OpenAPI declaration file content or url

openapi: 3.0.1
info:
  title: Preferences Core API
  version: 1.0.0
tags:
  - name: Preferences
    description: Operations for preferences
security:
  - api_key: [ ]
paths:
  /preferences:
    get:
      summary: Returns preferences based on parameters
      tags:
        - Preferences
      parameters:
        - $ref: '#/components/parameters/Accept'
      responses:
        '200':
          $ref: '#/components/responses/GetPreferencesListResponse'

components:
  parameters:
    Accept:
      name: Accept
      in: header
      description: Defines acceptable resource representations
      required: false
      schema:
        type: string
        default: application/json

  responses:
    GetPreferencesListResponse:
      description: Describes the success response for the get preferences operation
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/PreferencesListWithIds'

  securitySchemes:
    api_key:
      type: apiKey
      name: x-api-key
      in: header
  schemas:
    PreferencesType:
      type: string
      enum:
        - AWS
        - AZURE
        - TERRAFORM
        - GITLAB

    AWSPreferenceType:
      type: string
      enum:
        - ACCESS_KEY_ID
        - ACCESS_KEY_SECRET

    AzurePreferenceType:
      type: string
      enum:
        - CLIENT_ID
        - CLIENT_SECRET
        - SUBSCRIPTION_ID
        - TENANT_ID

    PreferencesListWithIds:
      type: array
      items:
        $ref: '#/components/schemas/PreferencesWithId'

    PreferencesWithId:
      allOf:
        - properties:
           id:
            type: string
        - $ref: '#/components/schemas/Preferences'

    Preferences:
      properties:
        programId:
          type: string
        projectId:
          type: string
        labels:
          type: array
          items:
            type: string
        type:
          $ref: '#/components/schemas/PreferencesType'
        preferences:
          type: array
          items:
            anyOf:
              - $ref: '#/components/schemas/AWSPreference'
              - $ref: '#/components/schemas/AzurePreference'
      required:
        - type
        - preferences

    Preference:
      type: object
      properties:
        name:
          type: string
        value:
          type: string
        encrypted:
          type: boolean
      required:
        - encrypted
        - name
        - value

    AWSPreference:
      allOf:
        - $ref: '#/components/schemas/Preference'
        - type: object
          properties:
            name:
              $ref: '#/components/schemas/AWSPreferenceType'

    AzurePreference:
      allOf:
        - $ref: '#/components/schemas/Preference'
        - type: object
          properties:
            name:
              $ref: '#/components/schemas/AzurePreferenceType'

Generation Details

{
  "dateLibrary": "java8",
  "java8": true,
  "library": "native",
  "sourceFolder": "src/main/java",
  "serializationLibrary": "jackson"
}

Steps to reproduce

I'm using this script:

#!/usr/bin/env bash

[ ! -f openapi-generator-cli.jar ] && wget https://repo1.maven.org/maven2/org/openapitools/openapi-generator-cli/5.1.1/openapi-generator-cli-5.1.1.jar -O openapi-generator-cli.jar

LAYER=$1
SERVICE_NAME=$2
SPEC_FILE=$3
VERSION=$4
MODULE_PACKAGE=$(echo "$LAYER.$SERVICE_NAME")
MODULE_ARTIFACT=$(echo "$LAYER-$SERVICE_NAME-spec-api")

TMP_DIR=$SERVICE_NAME

rm -fr $TMP_DIR
java -jar openapi-generator-cli.jar config-help -g java > help-java.txt
java -jar openapi-generator-cli.jar generate \
         --global-property models,modelTests=false,apis,supportingFiles \
         --additional-properties=apiPackage=io.$MODULE_PACKAGE.api \
         --additional-properties=artifactDescription=$SPEC_FILE \
         --additional-properties=artifactVersion=$VERSION \
         --additional-properties=artifactId=$MODULE_ARTIFACT \
         --additional-properties=groupId=io.$LAYER \
         --additional-properties=invokerPackage=io.$MODULE_PACKAGE.client \
         --additional-properties=modelPackage=io.$MODULE_PACKAGE.api \
         -i $SPEC_FILE \
         -g java \
         -c java-config.json \
         -o $TMP_DIR
cp -r .mvn $TMP_DIR

call it with:

sh generate-models.sh feature preferences Governance-Core-PreferencesAPI-Target-V1.0.yaml 1.0.0

Related issues/PRs

Suggest a fix

Start with generate-models.sh, java-config.json, and the provided OpenAPI specification, then reproduce the Java native generation using openapi-generator-cli 5.1.1. Check the generated models and compilation result for the anyOf preference schema; done means the expected AnyOfAWSPreferenceAzurePreference class is generated and the project builds successfully.