缺少指标字段值的类 - EclipseLink异常

Question

我收到了以下错误：

Exception [EclipseLink-43] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: Missing class for indicator field value [Component_Price_List] of type [class java.lang.String].
Descriptor: XMLDescriptor(com.celfocus.ufe.data.domains.productCatalog.PriceListItem --> [])

这是我的ComponentPriceList.class

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "Component_Price_List")
@Entity
@Table(name="PC_COMPONENT_PRICE_LIST")
public class ComponentPriceList
    extends PriceListItem
{
private static final long serialVersionUID = 1L;
}

我的PriceListItem.class是：

@Entity
@DiscriminatorColumn(name="PRICE_LIST_ITEM")
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name="PC_PRICE_LIST_ITEM")
public abstract class PriceListItem
    extends LaunchEntity
{

private static final long serialVersionUID = 1L;

      ......
 }

我不明白这是怎么发生的。我能做些什么来解决这个问题？感谢