Description michok34 2011-01-06 09:43:31 EST

Always reproducible.

Case :

@Entity
class ShoppingCart implements Serializable {
  @Id
  private String ID;
  
  @OneToMany(cascade = { CascadeType.ALL, CascadeType.REMOVE },
			   orphanRemoval = true, mappedBy = "cart")
  @MapKey(name = "keyref")
  private Map<String, Item> items = new HashMap<String, Item>();
  // Getters, Setters...
}

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(discriminatorType = DiscriminatorType.STRING, name = "type")
public abstract class Item implements Serializable {

  @Id
  private String ID;

  private String keyref;

  @ManyToOne
  @JoinColumn(name = "cart_ID", referencedColumnName = "ID")
  private ShoppingCart cart;
  // Getters, Setters...
}


@Entity
@DiscriminatorValue(value = "ConcreteItem")
public class ConcreteItem extends Item {
  ...
}

class SessionMgr {

  public void save(ShoppingCart cart) {
    ...
    EntityTransaction transaction = entitymanager.getTransaction();
    ...
    transaction.begin();
    entitymanager.persist(cart);
    transaction.commit();
  }

}

On commit the produced Stacktrace is:

javax.persistence.RollbackException: Exception [EclipseLink-34] (Eclipse Persistence Services - 2.0.1.v20100213-r6600): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: This class does not define a public default constructor, or the constructor raised an exception.
Internal Exception: java.lang.InstantiationException
Descriptor: RelationalDescriptor(com.blah.Item --> [DatabaseTable(item)])
	at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commitInternal(EntityTransactionImpl.java:102)
	at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:63)
	at com.blah.SessionMgr.save(SessionMgr.java:...)



However, if I modify my ShoppingCart like this:

@Entity
class ShoppingCart implements Serializable {
  @Id
  private String ID;
  
  @OneToMany(cascade = { CascadeType.ALL, CascadeType.REMOVE },
			   orphanRemoval = true, mappedBy = "cart")
  private List<Item> items = new ArrayList<Item>();

  // Getters, Setters...
}

There's no issue