Swagger OpenAPI Client Codegen issue with Polymorphism - spring-boot

Question

I am trying to generate the Swagger documentation and thin client for Java from the existing controllers that we have. Following are the sample classes:
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "clazz")
#JsonSubTypes({
#JsonSubTypes.Type(value = Cat.class, name = "Cat"),
#JsonSubTypes.Type(value = Fish.class, name = "Fish"),
#JsonSubTypes.Type(value = Frog.class, name = "Frog")
})
public interface Animal {
String getName();
int getType();
}
Here is the controller
#RestController
#RequestMapping("/animals")
public class AnimalController {
#GetMapping(value = "/")
public Animal[] getAnimalsByType(#RequestParam(required = false) String animalType) {
AnimalType type = StringUtils.isNotBlank(animalType) ? AnimalType.valueOf(animalType) : null;
Reflections reflections = new Reflections("com.xyz.openapi.server.model");
return reflections.getSubTypesOf(Animal.class).stream()
.map(animal -> {
try {
return animal.getDeclaredConstructor().newInstance();
} catch (InstantiationException | IllegalAccessException |
NoSuchMethodException | InvocationTargetException e) {
throw new RuntimeException(e);
}
})
.filter(animal -> animalType == null || type.index() == animal.getType())
.toArray(Animal[] :: new);
}
}
Here is the client code generation task from build.gradle
plugins {
id "java"
id "org.springframework.boot" version "2.3.1.RELEASE"
id "io.spring.dependency-management" version "1.0.9.RELEASE"
id "org.openapi.generator" version "5.1.0"
}
openApiGenerate {
inputSpec.set("$rootDir/api-docs.json")
outputDir.set("$rootDir/thinclient")
groupId.set("com.xyz.openapi")
id.set("openapi-thinclient")
version.set("0.0.1-SNAPSHOT")
apiPackage.set("com.xyz.openapi.thinclient.api")
invokerPackage.set("com.xyz.openapi.thinclient.invoker")
modelPackage.set("com.xyz.openapi.thinclient.model")
generatorName.set("java");
library.set("resttemplate")
configOptions.put("serializationLibrary", "jackson")
}
When I generate client code for java using gradle openApiGenerate, I am getting the client API generated as follows
#javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", date = "2021-05-24T19:20:33.823042600+05:30[Asia/Calcutta]")
#Component("com.xyz.openapi.thinclient.api.AnimalControllerApi")
public class AnimalControllerApi {
private ApiClient apiClient;
public AnimalControllerApi() {
this(new ApiClient());
}
#Autowired
public AnimalControllerApi(ApiClient apiClient) {
this.apiClient = apiClient;
}
public ApiClient getApiClient() {
return apiClient;
}
public void setApiClient(ApiClient apiClient) {
this.apiClient = apiClient;
}
/**
*
*
* <p><b>200</b> - OK
* #param animalType (optional)
* #return List<OneOfCatFishFrog>
* #throws RestClientException if an error occurs while attempting to invoke the API
*/
public **List<OneOfCatFishFrog>** getAnimalsByType(String animalType) throws RestClientException {
return getAnimalsByTypeWithHttpInfo(animalType).getBody();
}
}
The return type of the API is generated as List<OneOfCatFishFrog> instead of List<Animal>. Is there any change that I need to do to get this done? Please suggest!