Spring Data Repository without specifying Entity

Question

With Spring Data you can make a Repository for a given entity:

@Repository
public interface MyRepo extends CrudRepository<MyEntity, Long> {...}

But what if you have a lot of custom queries not tied to a specific Entity?

None of the below work:

@Repository
public interface MyRepo {...}

@Repository
public interface MyRepo extends CrudRepository {...}

@Component
public interface MyRepo extends Repository {...}

And so on..

Essentially what I want, is to be able to encapsulate some @Querys into an injectable class or interface.

Does this answer your question? Create spring repository without entity — marcioggs
– marcioggs, Commented Feb 21, 2024 at 9:23

Santiago Medina · Accepted Answer · 2020-03-29 04:53:59Z

You can use a generic entity superclass instead of a concrete entity. It's very usual to have an abstract superclass to declare the id of the entities or other common stuff.

@MappedSuperclass
public abstract class AbstractEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }   
}

Then you can create a repository like this and autowire where you need it:

public interface MyRepo extends JpaRepository<AbstractEntity, Long> {

    @Query("...")
    myQueryMethod();
}

That said, Spring Data interfaces are designed to work with a root entity. I think that if you want to avoid it, you should use the underlying JPA layer (that is, use the EntityManager to execute queries instead of a Spring Data Repository).

Collectives™ on Stack Overflow

Spring Data Repository without specifying Entity

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related