I have a simple project in which I want to achieve Contract first API approach with spring boot and OpenApi Code generator.

I am getting the below exception while trying to run my application after successfully building the Api. Anyone who has an idea on how to fix this issue, I will appreciate a lot.

Caused by: org.springframework.context.annotation.ConflictingBeanDefinitionException: Annotation-specified bean name 'usersApiController' for bean class [com.alexdev.springopenapi.server.UsersApiController] conflicts with existing, non-compatible bean definition of same name and class [com.alexdev.springopenapi.api.UsersApiController]

Below is my Api Specification and build.gradle files

Api Specifications

openapi: 3.0.3
info:
  title: User Management API
  version: '1.0'
  description: API for managing users

servers:
  - url: https://example.com/api

paths:
  /users:
    get:
      summary: Get all users
      description: Returns a list of all users
      responses:
        '200':
          description: Successful operation
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/User'
    post:
      summary: Create a new user
      description: Creates a new user
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/User'
      responses:
        '201':
          description: Successfully created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/User'
        '400':
          description: Invalid input

  /users/{userId}:
    get:
      summary: Get user by ID
      description: Returns a single user by ID
      parameters:
        - in: path
          name: userId
          description: ID of the user to return
          required: true
          schema:
            type: integer
      responses:
        '200':
          description: Successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/User'
        '404':
          description: User not found
    put:
      summary: Update user
      description: Updates an existing user
      parameters:
        - in: path
          name: userId
          description: ID of the user to update
          required: true
          schema:
            type: integer
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/User'
      responses:
        '200':
          description: Successfully updated
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/User'
        '404':
          description: User not found
        '400':
          description: Invalid input
    delete:
      summary: Delete user
      description: Deletes a user by ID
      parameters:
        - in: path
          name: userId
          description: ID of the user to delete
          required: true
          schema:
            type: integer
      responses:
        '204':
          description: Successfully deleted
        '404':
          description: User not found

components:
  schemas:
    User:
      type: object
      properties:
        id:
          type: integer
          format: int64
          example: 1
        username:
          type: string
          example: "john_doe"
        email:
          type: string
          example: "[email protected]"
        password:
          type: string
          example: "password123"

build.gradle

import org.openapitools.generator.gradle.plugin.tasks.GenerateTask


plugins {
    id 'java'
    id 'org.springframework.boot' version '3.2.5'
    id 'io.spring.dependency-management' version '1.1.4'
    id 'org.openapi.generator' version '7.5.0' apply false
}

apply plugin: 'org.openapi.generator'

group = 'com.alexdev'
version = '0.0.1-SNAPSHOT'

java {
    sourceCompatibility = '17'
}

configurations {
    compileOnly {
        extendsFrom annotationProcessor
    }
}

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    implementation 'org.springframework.boot:spring-boot-starter-validation'
    implementation 'org.springframework.boot:spring-boot-starter-web'
    compileOnly 'org.projectlombok:lombok'
    developmentOnly 'org.springframework.boot:spring-boot-devtools'
    developmentOnly 'org.springframework.boot:spring-boot-docker-compose'
    runtimeOnly 'com.mysql:mysql-connector-j'
    annotationProcessor 'org.projectlombok:lombok'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'

    implementation 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.5.0'

    compileOnly 'javax.validation:validation-api:2.0.1.Final'
    compileOnly 'javax.annotation:javax.annotation-api:1.3.2'
    compileOnly 'com.fasterxml.jackson.core:jackson-databind:2.17.0'
    compileOnly 'io.swagger.core.v3:swagger-annotations:2.2.21'
    compileOnly 'org.openapitools:jackson-databind-nullable:0.2.6'
    compileOnly 'javax.servlet:javax.servlet-api:4.0.1'
}


openApiGenerate {
    generatorName = "spring"
    library = "spring-boot"
    modelNameSuffix = ""
    id = "${project.name}" + "-api"
    groupId = project.group
    inputSpec = "${projectDir}/src/main/resources/openapi/openapi.yaml"
    configFile = "${projectDir}/src/main/resources/openapi/openapi-config.yaml"
    outputDir = "${buildDir}/generated/api"
    modelPackage = "${group}.${project.name}.dto"
    configOptions = [
            apiPackage: "${group}.${project.name}.api",
            serverPackage: "${group}.${project.name}.server",
    ]
}



tasks.register('openApiGeneratorApi', GenerateTask){
    apiPackage = openApiGenerate.configOptions.get().get('apiPackage')
    id = openApiGenerate.id
    modelNameSuffix = openApiGenerate.modelNameSuffix
    generatorName = openApiGenerate.generatorName
    inputSpec = openApiGenerate.inputSpec
    modelPackage = openApiGenerate.modelPackage
    library = openApiGenerate.library
    groupId = openApiGenerate.groupId
    outputDir = openApiGenerate.outputDir
}

tasks.register('openApiGeneratorServer', GenerateTask){
    apiPackage = openApiGenerate.configOptions.get().get('serverPackage')
    id = openApiGenerate.id
    modelNameSuffix = openApiGenerate.modelNameSuffix
    generatorName = openApiGenerate.generatorName
    inputSpec = openApiGenerate.inputSpec
    modelPackage = openApiGenerate.modelPackage
    library = openApiGenerate.library
    groupId = openApiGenerate.groupId
    outputDir = openApiGenerate.outputDir
}

openApiValidate {
    inputSpec = openApiGenerate.inputSpec
}

sourceSets {
    main{
        java {
            srcDir "$buildDir/generated/api/src/main/java"
        }
    }
}

tasks.register("buildApi", GradleBuild) {
    dependsOn('openApiGeneratorApi','openApiGeneratorServer')
    group = 'build'
    description = "Builds the API"
}


tasks.named('test') {
    useJUnitPlatform()
}