Can I annotate a member inherited from a superclass?

Question

If I have a class such as:

class Person {
  private String name;
  ...constructor, getters, setters, equals, hashcode, tostring...
}

Can I subc

Answer 1

Late answer, but I think overriding the getter method is a solid approach.

This can be a superclass for all tables which has an id field. If you serialize this object into JSON the id will always appear.

@MappedSuperclass
class ModelEntity {

    @Id
    @Column(
        name      = "id",
        updatable = false,
        nullable  = false
    )
    @GeneratedValue(strategy=GenerationType.AUTO)
    public Long id
}

But let's say you have the following objects (tables) Person and Occupation where Person has a one to many relationship with Occupation.

@Entity
@Table(name = "occupation")
Occupation extends ModelEntity {

    @Column
    String company

    @Column 
    String position
}

@Entity
@Table(name = "person")
Person extends ModelEntity {

    @Column
    String name

    @OneToMany
    Occupation occupation
}

Provided that id is present in all of the classes that extend ModelEntity if you were to serialize a Person object, you would get something like:

{
    "id" : 1,
    "name" : "Jordan",

    "occupation" : {
        "id" : 1,
        "company" : "WalMart",
        "position" : "Engineer"
    }

}

If you did not want the id to show up in the Occupation object, but you did want it to show up in the Person object, you can implement a getId() method at the Occupation class level, and apply desired annotations:

@Transient
public Long getId() {

    return id;   
}

Now your JSON would appear as follows: even though they both have an id column in the actual database:

{
    "id" : 1,
    "name" : "Jordan",

    "occupation" : {
        "company" : "WalMart",
        "position" : "Engineer"
    }

}