Please point me on how to add new collection types (e.g. Vavr / Guava)

[domdorn]

I'm trying to add the collection types ( Option, List, Tuple, etc.) from the vavr-library, but can't seem to find where to plug them in (https://www.vavr.io/vavr-docs/).
I already figured out on how to make the Future type work here https://dominikdorn.com/2020/05/spring-doc-openapi-swagger-vavr-future/
but I'm a little lost on how to make the collections types work.
It would be great if you could point me in the right direction!

This is what I tried so far:

1. I've already tried creating a io.swagger.v3.core.converter.ModelConverter but this leads to NPEs when swagger tries to clone the schema.
2. I also tried SpringDocUtils.getConfig().replaceWithClass(io.vavr.control.Option.class, java.util.Optional.class); but this seems to be unable to handle generics.
3. I tried to register the VavrModule with the ObjectMapper of SpringDoc/Swagger, but this also doesn't help ( Json.mapper().registerModule(new VavrModule()); )

Thx,
Dominik

[bnasslahsen]

@domdorn,

For collections, i assume you already have registred Jackson VavrModule.
If you need to use the mapping of Java Collection instead of the one of Vavr Collection. You can declare in your application:

static {
	SpringDocUtils.getConfig()
			.replaceWithClass(io.vavr.collection.Set.class, java.util.Set.class)
			.replaceWithClass(io.vavr.collection.List.class, java.util.List.class)
			.replaceWithClass(io.vavr.collection.Map.class, java.util.Map.class);
}

For io.vavr.control.Option, you can use a custom ModelConverter, as it is not available on ModelResolver._isOptionalType is only supporting com.google.common.base.Optional and java.util.Optional.
Here is a sample code for a ModelConverter.

@Component
public class VavrOptionSupportConverter implements ModelConverter {

@Override
public Schema resolve(AnnotatedType annotatedType, ModelConverterContext context, Iterator<ModelConverter> chain) {
	JavaType javaType = Json.mapper().constructType(annotatedType.getType());
	if (javaType != null) {
		Class<?> cls = javaType.getRawClass();
		if (io.vavr.control.Option.class.equals(cls)){
			annotatedType = new AnnotatedType()
					.type(javaType.containedType(0))
					.ctxAnnotations(annotatedType.getCtxAnnotations())
					.parent(annotatedType.getParent())
					.schemaProperty(annotatedType.isSchemaProperty())
					.name(annotatedType.getName())
					.resolveAsRef(annotatedType.isResolveAsRef())
					.jsonViewAnnotation(annotatedType.getJsonViewAnnotation())
					.propertyName(annotatedType.getPropertyName())
					.skipOverride(true);
			return this.resolve(annotatedType, context, chain);
		}
	}
	return (chain.hasNext()) ? chain.next().resolve(annotatedType, context, chain) : null;
}

}

[domdorn]

perfect, thank you @bnasslahsen ! While the replaceWithClass didn't had the intended result (e.g. it lost type information and thus all collections became untyped arrays), your code of the ModelConverter works good enough so I could also implement it for the collection types. Will create a blog post with the full code soon and give attribution to you @bnasslahsen !

Hi @domdorn, did you write a blog post for collection types. I am also facing the same problem so it would be a great help for me

hi @domdorn found your gist here https://gist.github.com/domdorn/bddf5ce1348464179fdd4ffc65b70870

thanks, it helped.

Commenting it here so that others will be able to find it easily

[domdorn]

The post is supposed to be this one:
https://dominikdorn.com/2020/05/spring-doc-openapi-swagger-vavr-future/
but apparently the github-gist plugin for wordpress fails for some reason.. anyway, you've found the right gist :-)