openapi-generator: [java] Combining "properties" and "additionalProperties" in one class generates broken Jackson mapping.

Description

If using both “properties” and “additionalProperties”, the generated class extends HashMap and contains plain properties. Like this:

public class Example extends HashMap<...>  {
  @JsonProperty("a")
  private String a;
  ...
}

Such a class cannot be meaningfully deserialised using Jackson. Jackson puts all the fields as key/value pairs into the HashMap ignoring the plain fields. In provided example getA() would return “null”, while get(“a”) contains the value.

openapi-generator version

Used version: openapi-generator-maven-plugin : 3.3.3

OpenAPI declaration file
Example:
  type: object
  properties:
    a:
    type: string
  additionalProperties: true
Suggest a fix/enhancement

I would suggest to generate such a class (which has both “properties” and “additionalProperites”) as:

public class Example {
  private String a;
  private HashMap<> otherProperties;
  ...
}

Similar suggestion in “swagger-codegen” project: https://github.com/swagger-api/swagger-codegen/issues/5187

About this issue

  • Original URL
  • State: closed
  • Created 6 years ago
  • Reactions: 27
  • Comments: 23 (10 by maintainers)

Commits related to this issue

Most upvoted comments

I think that having a member of HashMap instead of extending HashMap would address the issue. @JsonAnyGetter and @JsonAnySetter are designed for this exactly. Like @FatCash suggested, there could be a feature flag that would allow backward compatibility (though it seems broken right now anyway)

+8
harel-e on Aug 13, 2020

Any updates on this?

+8
claudemamo on Apr 9, 2019

Any updates on this issue?

+3
wakedeer on Jul 18, 2020

Also having problems with serialize/deserialize properly because of this. Desired approach would be to populate a mustache flag like {{hasAdditionalProperties}} on class level (not vars level), similar to {{isMapContainer}} which is currently true if additionalProperties: true Then we could use it however we want in mustache to add the otherProperties field and necessary json annotations and builders etc…

The automatic extends HashMap<...> should not be there, instead users can add that themselves in mustasche by checking the {{hasAdditionalProperties}} flag.

+2
FatCash on Sep 3, 2019

We are facing the very same issue using openapi-generator-gradle-plugin : 4.0.1 and the jaxrs-jersey generator.

Are there any workarounds beside not using both (i.e. properties and additionalProperties) at the same time? Are there any plans to fix it?

Thanks!

+2
vandeseer on Jul 7, 2019

Hello, I created this pull request a long time ago and did not receive any approval at the time. If anybody wants to take it over, feel free.

+1
benfonty on Jun 7, 2023

Hi, this issue is blocking my team as well. @Zomzog , @banlevente , @borsch , @javisst , @cachescrubber , @welshm , @MelleD, @atextor, @manedev79, What is the status on this issue? I tried to contact @jameswynn with no success. I’m happy trying to merge this pull request if need be.

+1
loiccara on Sep 14, 2022

curious if this was ever fixed?

+1
cgfarmer4 on Feb 23, 2021
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