[BUG][JAVA][NATIVE] Pojo with Set uses Arraylist, wrong datatype in for loop

[RInverid]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
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Description

When using an object with a set, I ran into two separate issues:

1. The generated add to set method assigns ArrayList to the set, which fails compilation
2. The generated toUrlQueryString uses the wrong datatype in a for loop with the set, which fails compilation

openapi-generator version

6.4.0

OpenAPI declaration file content or url

https://gist.github.com/RInverid/417213fbba82782204ddce87b22d5d62

Generation Details

Java, native http library

Steps to reproduce

Try to build the generated client, it fails to build due assigning a list to a set, and looping over the enum instead of an array

Suggest a fix

Issue 1:
variable is correctly assigned here and incorrectly assigned here. Caused by commit fd45b74

Issue 2:
Datatype is incorrect here, in this case it should be an enum.

[mvanglabbeek]

I experience the same issue. Version 6.2.1 initialized the java.util.Set with this.fieldName = new LinkedHashSet<>();, which is correct. Version 6.3.0 and version 6.4.0 initializes the java.util.Set with this.fieldName = new ArrayList<>(); (without importing java.util.ArrayList), which is broken code.

[RInverid]

@wing328 the official maintainer of Java (Java 11 Native HTTP client) @bbdouglas, has been inactive since 2019. Maybe this API client should be marked as unsupported?

[wing328]

I've filed #14961 to fix the issue. Please pull it to give it a try. You may need the option --additional-properties supportUrlQuery=false to skip the toUrlQuery method, e.g.

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g java --library native -i https://gist.githubusercontent.com/RInverid/417213fbba82782204ddce87b22d5d62/raw/d85d89ec41db9e6a93400426ffc8178b5879305b/spec.json -o /tmp/native --additional-properties supportUrlQuery=false

[wing328]

Maybe this API client should be marked as unsupported?

The native library support is maintained by the community. There has been a lot of enhancements (PRs) so I don't think we should deprecate it.

We appreciate @bbdouglas for contributing the first version of native library support

[wing328]

the fix has been merged and will be included in the upcoming 6.5.0 release

[RInverid]

Yeah that fixed the first issue, and the additional property circumvents the second issue. Thanks a bunch :)