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

[roostapour]

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

[wing328]

Please try the option generateAliasAsModel, which will generate array, map as models

[roostapour]

Thanks for your answer @wing328 . I tried both

<configuration>
    <generateAliasAsModel>true</generateAliasAsModel>
</configuration>

and

<configuration>
    <configOptions>
         <generateAliasAsModel>true</generateAliasAsModel> 
    </configOptions>
</configuration>

But none of them worked. How should I set the generateAliasAsModel option?

[wing328]

Doc: https://github.com/OpenAPITools/openapi-generator/tree/master/modules/openapi-generator-maven-plugin

I think the first one should work ...

[roostapour]

@wing328 I realized if I define a Map of string to string in the yaml file like the following then generateAliasAsModel works.

Messages:
  type: object
  additionalProperties:
    type: string

But if the value is an object or ref (which I need) like the the following then generateAliasAsModel does not work and doesn't generate Messages

Messages:
  type: object
  additionalProperties:
    type: object

or

Messages:
  type: object
  additionalProperties:
    $ref: '#/components/schemas/Message'

[roostapour]

Just to add, I do have the same issue on javascript side. Having the following version in my package.json

"devDependencies": {
    "@openapitools/openapi-generator-cli": "^1.0.13-4.3.1"
}

and running with --generate-alias-as-model flag, with the same yaml file behaves exactly the same as Java side. For Map of string to string it works but for Map of string to object/ref it does not generate the model.

[abhijith-prabhakar]

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

[roostapour]

Can someone please answer this?

[wing328]

@roostapour based on what you provided, looks like it's a bug. A good starting point is https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java and search for isGenerateAliasAsModel

[yahyavi]

Hello,
We have a similar issue trying to generate a Map from our YAML file (v3). Is there a document/example on how to generate maps/dictionaries properly?

[chrylis]

Confirmed that as of 4.3.1 classes are generated, but:

• The classes incorrectly extend CollectionType<Object> instead of whatever they're a collection of.
• The above-mentioned initializer error.
• When the classes are referred to in code, they're replaced with Object.
• The buggy behavior applies to array-of types in addition to additionalProperties.

[helango-seabiscuit]

Any update on the issue? Is this fixed? Facing same issue

[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

[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: