When all columns of an @Embedded field are NULL (JPA / Hibernate)

[Roel De Nijs]

Hibernate sets the field in the parent object to null. Even if this field is declared final and initialized.

@Embeddable
public class Address {
  private String street;
  private String postalCode;
  private String city;
}

@Entity
public class Person {
  @Embedded
  private final Address home = new Address();
}

So if street, postalCode and city are all NULL, the home field will be set to null. That's not the behavior I'm looking for. I want an instance with all its fields set to null.


A possible workaround: handling this possible null value in the getter of this field.

public Address getHomeAddress() {
  return home == null ? new Address() : home;
}

But that looks very strange (certainly for a developer who doesn't know of this issue), because the field is initialized and final.


Another workaround: adding a dummy primitive variable to the @Embeddable class and annotating it with @org.hibernate.annotations.Formula, so not all columns of the @Embedded field are NULL (and thus the field in the Person class is never set to null):

@Embeddable
public class Address {
  @Formula("0")
  private int dummy;

  private String street;
  private String postalCode;
  private String city;
}

Unfortunately this annotation has no JPA alternative and we prefer not to use Hibernate specific annotations, because that would lock us to a specific persistence provider


Any other workarounds or alternatives?

[Andreas Martin]

Simply:

    public Address getHomeAddress() {
        if (home == null) {
            this.home = new Address();
        }
        return home;
    }
}

[Al Hobbs]

Better late than never I suppose.