@TypeDef is supposed to allow users to define standard types to be used for specific classes. However, due to a bug in implementation, it simply doesn't work for enums.
Enums are implicitly handled by the JPA spec. However, if a @TypeDef is defined for a particular enum, it will never be picked up due to bug in org.hibernate.cfg.annotations.SimpleValueBinder .
This class has a concept of a "explicitType", i.e., a type that was explicitly specified for a property. However, even if @EnumType is not used to annotate a property, method setType(XProperty,XClass) considers the property as annotated with it. Then, when fillSimpleValue() is called as part of second-pass compilation, the ternary in line 344 chooses org.hibernate.type.EnumType instead of the enum FQN, causing any @TypeDef to be ignored.
This behaviour should be fixed by considering a non-annotated enum property as implicitly typed, not explicitly. Then, the resolution order should be changed to explicitType -> returnedClassName -> implicitType. This would preserve default, expected behaviour for regular enums, while allowing @TypeDef to be used for enums as well.
hibernate-jpa-2.0-api:1.0.1-Final; hibernate-core:4.1.0.Final; hibernate-entitymanager:4.1.0.Final