The following exception is thrown when an entity exists with a collection containing a parameterized type:

Caused by: org.hibernate.annotations.common.AssertionFailure: Fail to process type argument in a generic declaration. Member : cp.CentralizedContract#children Type: class sun.reflect.generics.reflectiveObjects.WildcardTypeImpl
at org.hibernate.jpa.internal.metamodel.AttributeFactory$PluralAttributeMetadataImpl.getClassFromGenericArgument(AttributeFactory.java:890)
at org.hibernate.jpa.internal.metamodel.AttributeFactory$PluralAttributeMetadataImpl.<init>(AttributeFactory.java:800)
at org.hibernate.jpa.internal.metamodel.AttributeFactory$PluralAttributeMetadataImpl.<init>(AttributeFactory.java:775)
at org.hibernate.jpa.internal.metamodel.AttributeFactory.determineAttributeMetadata(AttributeFactory.java:555)
at org.hibernate.jpa.internal.metamodel.AttributeFactory.buildAttribute(AttributeFactory.java:93)
at org.hibernate.jpa.internal.metamodel.MetadataContext.wrapUp(MetadataContext.java:227)
at org.hibernate.jpa.internal.metamodel.MetamodelImpl.buildMetamodel(MetamodelImpl.java:96)
at org.hibernate.jpa.internal.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:148)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:865)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:843)
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:398)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:842)
at org.hibernate.jpa.HibernatePersistenceProvider.createContainerEntityManagerFactory(HibernatePersistenceProvider.java:152)
at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:67)

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Example:

public abstract class CentralizedContract extends Contract{

@ManyToOne(cascade=

, fetch=FetchType.LAZY)
@JoinColumn(name="FK_PARENT", referencedColumnName="FK_CONTRACT") //it's a relationship [FK_PARENT *<=>1 FK_CONTRACT]
private CentralizedContract parent;

@OneToMany(fetch = FetchType.LAZY, cascade=CascadeType.ALL, mappedBy="parent", targetEntity=CentralizedContract.class)
private List<? extends CentralizedContract> children;