Question

I have an Entity and a related IdClass.

@Entity
@IdClass(MyEntityId.class)
class MyEntity {
    @Id @ManyToOne You you; <---------------------|
    @Id @ManyToOne He he; ------------------------+---------|
}                                                 |         |
                                                  | @@?     |
class MyEntityId {                                |         | @@?
    Long you; <-----------------------------------|         |
    Long he; <----------------------------------------------|
}

Is it OK without any MapsId or something?
Does JPA automatically maps you to you and he to he?

Answer 1

The types must match. I.e. they should be Long in your entity. Apart from that – yes, they are matched by name.