OpenAPITools / OpenAPITools/openapi-generator

[BUG] Generated Kotlin client do not work with Spring Boot 4

Open
#22,411 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Issue: Bug
Dominant language
Java
Stars
26.8k
Forks
7.7k
PR merge metrics
PR metrics pending

Description

Description

Generator creates code like this:

 protected inline fun <reified I : Any, reified T: Any?> request(requestConfig: RequestConfig<I>): ResponseEntity<T> {
        return prepare(defaults(requestConfig))
            .retrieve()
            .toEntity(object : ParameterizedTypeReference<T>() {})
 }

This code das not compile anymore in Spring Web 7 (used by Spring Boot 3):

None of the following candidates is applicable:
fun <T : Any> toEntity(bodyType: Class<T>): ResponseEntity<T>
fun <T : Any> toEntity(bodyType: ParameterizedTypeReference<T>): ResponseEntity<T>`
Propsed solution

It should be enough to change the outer bounds from Any? to Any like this:

    protected inline fun <reified I : Any, reified T: Any> request(requestConfig: RequestConfig<I>): ResponseEntity<T> {
        return prepare(defaults(requestConfig))
            .retrieve()
            .toEntity(object : ParameterizedTypeReference<T>() {})
    }
openapi-generator version

7.17.0

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start from the generated Kotlin request helper shown in the issue and locate the generator template that emits it. Verify the generated client against Spring Web 7 or Spring Boot 4, then confirm that the resulting Kotlin code compiles and preserves the expected ResponseEntity behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
kotlin, spring-boot
Domain
api
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
48/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.