Inferred type 'S' for type parameter 'S' is not within its bound; should extend 'ua.com.store.entity.Country
Spring documentation defines methods getOne as follows
<S extends T> Optional<S> findOne(Example<S> example)
In your method your input parameter is 'id' of type int but not bounded to interface Example.
To find an entity with it 'id' you can use the method
Optional<T> findById(ID id)
According to your implementation you may write it
@Override
public Country findOne(int id) {
return dao.findById(id);
}
It is possible to be relevant about spring-boot version. I meet the same issue when my spring-boot version is 2.0.1.RELEASE. But after change the spring-boot version to the 1.5.9.RELEASE, it is resolved.
A 100% working solution is following:
@Override
public Country findOne(int id) {
return dao..findById(id).orElse(null);
}