Hibernate version: 3.2.5

How would I map the following Map<EnumA, List<ClassB>>???

I may be way off, but, currently I have something like the following.



Now the error that I receive is pretty obvious:


However, I can't seem to find any mapping element that will allow me to specify that the value of the map is a java.util.List that holds numerous my.ClassB objects (instead of using the one-to-many with a class attribute of my.ClassB).

Any help or direction would be greatly appreciated.

Any ideas???? Or is this not possible? Any help would be greatly appreciated.

I tried something very similar and could not make it work. I had to create a separate class to contain the list of entities. Here are the details.
Java
private Map<MetadataString, ParentFieldAssociations> fieldAssociations = new HashMap<MetadataString,ParentFieldAssociations>();

Mappings
<class name="collective.asset.ParentFieldAssociations" table="ParentFieldAssociations">
<id name="id" unsaved-value="null">
<generator class="native" />
</id>
<list name="fields" table="ParentFieldsList">
<key column="parentFieldId"/>
<list-index column="idx"/>
<many-to-many class="collective.asset.AbstractMetadataField"/>
</list>
</class>


<class name="collective.asset.ParentPropertySelectionField" discriminator-value="ParentProperySelectionField">
<map name="fieldAssociations" table="ParentMetadataFieldsMap">
<key column="id" />
<map-key-many-to-many column="stringId" class="collective.asset.MetadataString"/>
<many-to-many column="fieldAssociationId" class="collective.asset.ParentFieldAssociations"/>
</map>
</class>

Dkallstrom, thank you for your post. I was afraid that was going to be the answer. I just don't quite understand why Hibernate does not allow for mapping nested collections (e.g. Map<String, List<String>> or the like); However, that intended functionality is available to you by simply wrapping the nested Collection in some type of "middleman" object that contains your Collection. It just doesn't quite add up. Maybe it will be addressed at a later time (or am I the only one wanting/needing to do this?) Thanks again for your post and assistance.