[BUG] [JAVA] "additionalProperties" does not generate a HashMap Model, openapi: 3.0.2

Description

I am using “additionalProperties” in my yaml file as below.

openapi: 3.0.2
....
components:
  schemas:
    Messages:
      type: object
      additionalProperties:
        $ref: '#/components/schemas/Message'
    Message:
      type: object
      properties:
        code:
          type: integer
        text:
          type: string

But when running mvn clean package, no class is being created for Messages. I was expecting to see a class like :

public class Messages extends HashMap<String, Object> {
......
}

in org.openapitools.client.model.Messages the same as other classes generated based on the yaml file. I tried additionalProperties: true and additionalProperties: {} but none of them worked. It seems like a bug

my pom.xml for openapi-generator and swagger versions

<dependency>
  <groupId>io.swagger</groupId>
  <artifactId>swagger-annotations</artifactId>
  <version>1.6.1</version>
</dependency>
....
<plugin>
  <groupId>org.openapitools</groupId>
  <artifactId>openapi-generator-maven-plugin</artifactId>
  <version>4.3.1</version>
  <executions>
    <execution>
      <goals>
        <goal>generate</goal>
      </goals>
        ...
    </execution>
  </executions>
</plugin>

Command line used for generation

mvn clean package

[JaquelineP]

Any updates? I tried it with openapi-generator-maven-plugin 5.4.0. and get an compile time error. When adding an item to the hashmap it tries to initialize the Map. Here’s a snippet of the generated code:

[Praveen2518]

It is slightly different issue in JAX-RS. I am working on v4.3.1 and OpenAPI v2

It generates Message.java but the pojo where messages are included does not have type information. This generates a compile error.

private Message messages = new HashMap<>();

I traced it to below code on pojo.mustache

private {{{datatypeWithEnum}}} {{name}}{{#defaultValue}} = {{{.}}}{{/defaultValue}};

I am not sure how HashMap<> is getting substituted here. Please let me know if you want me to create a separate issue for this

Hi, Did you solve this issue how to remove that hashMap how it is substituting.i am also stuck at this problem and I am using open api 5.1.0 version