Question

I want to mapping a class to a primitive type

@Entity
@Table(name="PERSON")
public class Person implements Serializable {
    ...
   private Email email = null;
    ...
   @Column(name="email")
   public Email getEmail() {
      return email;
   }
   public void setEmail(Email email) {
      this.email=email;
   }
}

In this example I want to save the email like a String

I wish something like:

interface someInterface{

   String getValue();
   void setValue(String p);

}

Then if I implement this interface in Email it can be save and loaded transparently (I haven’t find something like this).

I don’t want to serialize the class

I use Email as a example, but I have in mind many other class, to little to be a whole entity.

Any idea?

Answer 1

JPA2.1 provides AttributeConverter which means that a field can be marked with a converter persisting it as, for example, a String. All JPA implementations have their own variant currently, but DataNucleus JPA provides the JPA2.1 feature already, see the foot of this page.