Java domain classes generated using swagger-codegen don't extend their base classes.
http://swagger.io/specification/ - please see "Composition and Inheritance (Polymorphism)" part.
Here's an example of required changes to thomson-reuters-world-check-one-api.v1.yaml file in order to fix NewCase model - which extends UpdateCase model - generation (please note that NewCase isn't the only model with the issue):
# # Definitions for Case domain # =========================== # UpdateCase: type: object discriminator: updateCaseType # <---- new description: | Defines Case data that can be sent when updating a Case. # ... omitting some code here # ... # UpdateCase definition continued: required: - name - updateCaseType # <---- new - providerTypes properties: ...
P.S.: I'm not a Swagger expert, so there might be a reason why you have missing discriminator property, but changes above helped me to generate correct java classes.