Question

I want to copy the entity’s UUID, generated at run time to another field.
The entity id is generated via the code described bellow:

package eclipselink.example;
public class UUIDSequence extends Sequence implements SessionCustomizer {
    public UUIDSequence() {
        super();
    }
    public UUIDSequence(String name) {
        super(name);
    }
    @Override
    public Object getGeneratedValue(Accessor accessor,
            AbstractSession writeSession, String seqName) {
        return UUID.randomUUID().toString().toUpperCase();
    }
    ...
    public void customize(Session session) throws Exception {
        UUIDSequence sequence = new UUIDSequence("system-uuid");
        session.getLogin().addSequence(sequence);
    }
}

Persitence.xml:

property name="eclipselink.session.customizer" value="eclipselink.example.UUIDSequence"

The entity:

public abstract class MyEntity{
    private String id;
    private String idCopy;

    @Id
    @Basic(optional = false)
    @GeneratedValue(generator="system-uuid")
    @XmlElement(name = "ID")
    public String getId() {
        return id;
    }
}

How can I instruct JPA (Eclipse-link) to copy the UUID generated at runtime to idCopy field as well?

Answer 1

I’m not 100% sure this will work (I don’t know if EclipseLink calls the setter or assigns the field directly), but give this a try:

public abstract class MyEntity{
    private String id;
    private String idCopy;

    @Id
    @Basic(optional = false)
    @GeneratedValue(generator="system-uuid")
    @XmlElement(name = "ID")
    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
        this.idCopy = id;
        // or
        // this.setIdCopy(id);
    }
}