[Spring] Maven plugin v3 generates for Spring classes with Swagger v2

Description

When I tried generate model and API interface for Spring language with Maven plugin so I got classes with Swagger v2 annotation. But when I used Java language then plugin generated right Swagger annotation version.
Example of wrongly generated class:

package cz.test.openapi.rest.model;

import java.util.Objects;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonCreator;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import org.springframework.validation.annotation.Validated;
import javax.validation.Valid;
import javax.validation.constraints.*;

/**
 * Pet
 */
@Validated


public class Pet   {
  @JsonProperty("id")
  private Long id = null;

  @JsonProperty("name")
  private String name = null;

  @JsonProperty("tag")
  private String tag = null;

  public Pet id(Long id) {
    this.id = id;
    return this;
  }

  /**
   * Get id
   * @return id
  **/
  @ApiModelProperty(required = true, value = "")
      @NotNull

    public Long getId() {
    return id;
  }

  public void setId(Long id) {
    this.id = id;
  }

  public Pet name(String name) {
    this.name = name;
    return this;
  }

  /**
   * Get name
   * @return name
  **/
  @ApiModelProperty(required = true, value = "")
      @NotNull

    public String getName() {
    return name;
  }

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

  public Pet tag(String tag) {
    this.tag = tag;
    return this;
  }

  /**
   * Get tag
   * @return tag
  **/
  @ApiModelProperty(value = "")
  
    public String getTag() {
    return tag;
  }

  public void setTag(String tag) {
    this.tag = tag;
  }


  @Override
  public boolean equals(java.lang.Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    Pet pet = (Pet) o;
    return Objects.equals(this.id, pet.id) &&
        Objects.equals(this.name, pet.name) &&
        Objects.equals(this.tag, pet.tag);
  }

  @Override
  public int hashCode() {
    return Objects.hash(id, name, tag);
  }

  @Override
  public String toString() {
    StringBuilder sb = new StringBuilder();
    sb.append("class Pet {\n");
    
    sb.append("    id: ").append(toIndentedString(id)).append("\n");
    sb.append("    name: ").append(toIndentedString(name)).append("\n");
    sb.append("    tag: ").append(toIndentedString(tag)).append("\n");
    sb.append("}");
    return sb.toString();
  }

  /**
   * Convert the given object to string with each line indented by 4 spaces
   * (except the first line).
   */
  private String toIndentedString(java.lang.Object o) {
    if (o == null) {
      return "null";
    }
    return o.toString().replace("\n", "\n    ");
  }
} 

Swagger-codegen version

swagger-codegen-maven-plugin 3.0.20 (but it same for 3.0.21-SNAPSHOT)

Swagger declaration file content or url

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>cz.test</groupId>
    <artifactId>openApi</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>openApi</name>
    <description>Test project for test OpenAPI 3 interface and model for Spring </description>

    <properties>
        <maven.compiler.target>11</maven.compiler.target>
        <maven.compiler.source>11</maven.compiler.source>
        <base.package>cz.test.openapi</base.package>
    </properties>
    
    <build>        
        <plugins>           
            <plugin>
                <!-- This 2019 version is required for OpenAPI 3 -->
                <groupId>io.swagger.codegen.v3</groupId>
                <artifactId>swagger-codegen-maven-plugin</artifactId>
                <version>3.0.20</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                        <configuration>
                            <inputSpec>${basedir}/src/main/resources/openApi/petstore.yaml</inputSpec>
                            <!-- <language>java</language> -->
                            <language>spring</language>
                            <packageName>cz.test.openapi</packageName>
                            <modelPackage>cz.test.openapi.rest.model</modelPackage>
                            <apiPackage>cz.test.openapi.rest.api</apiPackage>
                            <invokerPackage>cz.test.openapi.rest.invoker</invokerPackage>
                            <output>target/generated-sources</output>
                            
                            <generateApis>true</generateApis>
                            <generateModels>true</generateModels>
                            <generateSupportingFiles>false</generateSupportingFiles>
                            <generateModelTests>false</generateModelTests>
                            <generateModelDocumentation>false</generateModelDocumentation>
                            <generateApiTests>false</generateApiTests>
                            <generateApiDocumentation>false</generateApiDocumentation>
                            
                            <configOptions>
                                <groupId>${project.groupId}</groupId>
                                <artifactId>${project.artifactId}</artifactId>
                                <artifactVersion>${project.version}</artifactVersion>
                                <!-- <library>resttemplate</library> -->
                                <hideGenerationTimestamp>true</hideGenerationTimestamp>
                                <java8>true</java8>
                                <dateLibrary>java8</dateLibrary>
                                <modelPackage>cz.test.openapi.rest.model</modelPackage>
                                <apiPackage>cz.test.openapi.rest.api</apiPackage>                                
                                <interfaceOnly>true</interfaceOnly>
                            </configOptions>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

OpaneAPI yaml

openapi: "3.0.0"
info:
  version: 1.0.0
  title: Swagger Petstore
  license:
    name: MIT
servers:
  - url: http://petstore.swagger.io/v1
paths:
  /pets:
    get:
      summary: List all pets
      operationId: listPets
      tags:
        - pets
      parameters:
        - name: limit
          in: query
          description: How many items to return at one time (max 100)
          required: false
          schema:
            type: integer
            format: int32
      responses:
        '200':
          description: A paged array of pets
          headers:
            x-next:
              description: A link to the next page of responses
              schema:
                type: string
          content:
            application/json:    
              schema:
                $ref: "#/components/schemas/Pets"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
    post:
      summary: Create a pet
      operationId: createPets
      tags:
        - pets
      responses:
        '201':
          description: Null response
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
  /pets/{petId}:
    get:
      summary: Info for a specific pet
      operationId: showPetById
      tags:
        - pets
      parameters:
        - name: petId
          in: path
          required: true
          description: The id of the pet to retrieve
          schema:
            type: string
      responses:
        '200':
          description: Expected response to a valid request
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pet"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
components:
  schemas:
    Pet:
      type: object
      required:
        - id
        - name
      properties:
        id:
          type: integer
          format: int64
        name:
          type: string
        tag:
          type: string
    Pets:
      type: array
      items:
        $ref: "#/components/schemas/Pet"
    Error:
      type: object
      required:
        - code
        - message
      properties:
        code:
          type: integer
          format: int32
        message:
          type: string

Start by running the swagger-codegen-maven-plugin configuration in pom.xml against the provided OpenAPI YAML and compare Spring output with Java output. Inspect the generated Pet class and related API files; done means Spring generation uses the expected annotation version rather than Swagger v2 annotations.