Java JPA存储库和多态

Question

I have following object model and repository in my application:

@Entity
class Vehicle {}

class Car extends Vehicle {}
class Truck extends Vehicle {}

@Repository
public interface VehicleRepository extends JpaRepository<Vehicle, Long> {}

What I'm trying to get working is following:

Vehicle t = new Truck();
VehicleRepository r = new VehicleRepository();
r.save(t);

How to get this code working without need of copying Truck to Vehicle object?

Thanks!

Answer 1

As Alan Hay linked to you, you need to set up the inheritance :

1. Add @Entity to all classes
2. Add @Inheritance to your Vehicle class to enable inheritance for the entityManager, If you're not supposed to store any raw Vehicle, you can use @MappedSuperClass

For the rest i relink the link that Alan Hay provided : https://en.wikibooks.org/wiki/Java_Persistence/Inheritance