CODEWITHSUNDEEP
javajakarta-eeeclipselinkuuid
Sogawa-sps
Sogawa-sps

Reputation: 159

EclipseLink's @UuidGenerator leads to NullPointerException

I've tried to start using EclipseLink's @UuidGenerator annonation for ID generation but it failed with NPE.

I'm using Java EE 6 + GlassFish 4.1. Entity were created from servlet. EclipseLink version is 2.6.0-M3. Simple long id "@GeneratedValue(strategy = GenerationType.AUTO)" works fine.

Entity code:

@Entity
@UuidGenerator(name="QUANTITY_GEN")
public class Quantity implements Serializable 
{
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(generator = "QUANTITY_GEN")
    private String id;

...

}

Servlet code:

@WebServlet(name = "Qtest", urlPatterns =
{
    "/Qtest"
})
public class Qtest extends HttpServlet
{
    @EJB
    private QuantityFacade quantityFacade;

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
        ...

        Quantity qt = new Quantity();
        quantityFacade.create(qt);

        ...
    }
}

Trace:

Caused by: java.lang.NullPointerException
    at org.eclipse.persistence.internal.sequencing.SequencingManager.getNextValue(SequencingManager.java:1067)
    at org.eclipse.persistence.internal.sequencing.ClientSessionSequencing.getNextValue(ClientSessionSequencing.java:70)
    at org.eclipse.persistence.internal.descriptors.ObjectBuilder.assignSequenceNumber(ObjectBuilder.java:361)
    at org.eclipse.persistence.internal.descriptors.ObjectBuilder.assignSequenceNumber(ObjectBuilder.java:320)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.assignSequenceNumber(UnitOfWorkImpl.java:486)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNotRegisteredNewObjectForPersist(UnitOfWorkImpl.java:4290)
    at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.registerNotRegisteredNewObjectForPersist(RepeatableWriteUnitOfWork.java:518)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:4235)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:496)
    at com.sun.enterprise.container.common.impl.EntityManagerWrapper.persist(EntityManagerWrapper.java:287)
    at uuidtest.AbstractFacade.create(AbstractFacade.java:24)

Please advise maybe there is some obvious error?

Upvotes: 2

Views: 1520

Answers (2)

Sacky San
Sacky San

Reputation: 1662

I used following code to get rid of the issue. Using a default constructor gave me problems in cloning entities with composite keys while using BeanUtils.copyProperties(). Hence i used @PrePersist. This is called just before a row is created in database for the first time

@MappedSuperclass
@Getter
@Setter
public abstract class AbstractMasterUUIDEntity extends AbstractMasterEntity<String> {

    @Id
    private String id;

    @PrePersist
    public void generateId() {
        if(this.id == null ) {
            this.id = UUID.randomUUID().toString();
        }
    }

}

Upvotes: 1

Sogawa-sps
Sogawa-sps

Reputation: 159

It seems it's really EclipseLink's bug and it will hardly be fixed soon so I've used a work around - direct id generation as described here http://blog.xebia.com/2009/06/03/jpa-implementation-patterns-using-uuids-as-primary-keys/ 

@Id
private String id;

public AbstractBaseEntity() {
    this.id = UUID.randomUUID().toString();
}

Upvotes: 3

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