At my work we are creating a Type Safe Enumeration wrapper around a List. We are using JDK 1.4.2 and our wrapper holds an instance to List as opposed to implementing List and overriding its methods with our own type safe functionality.

I know it is mentioned in the Hibernate documentation that the superclasses for collections are preferred when mapping these collections in a *.hbm.xml. Will this type of Type Safe Enumeration cause problems when trying to map a class that has one of these Type Safe Enumeration collections of another object? Should we be implementing List as opposed to holding an instance, would this make a difference in the Hibernate mapping? Or is this purely a job for a custom type?

Thanks,

-jay

Your terminology is a little confusing. Are you talking about a type-safe collection? Or an "enum" type (i.e. a value type) implemented as a class?

Or maybe a type-safe implementation of java.util.Enumeration?

Sorry...I am little retarded in this area.

We are trying to create Type Safe Collections. So for instance, we are creating implementations of a Collection that only allow the addition of a particular type of object. So we have a core TO that has these Type Safe Collections that hold different types of TOs. Each special TO has a special Type Safe Collection that only allows that type of object in the collection.

Therefore we may have a person TO that may hold a Type Safe Collection of Address TOs.

What would it take to represent in Hibernate?

Thanks,

-jay

Would custom types work in this scenario?

Thanks,

-jay

Have you looked into Java 5 generics, and whether it can do the trick for you?

The reason for using the List/Map/etc interfaces in your POJOs is that Hibernate will then use it's own implementation allowing lazy initialization etc.

From what I remember you could use a concrete implementation (such as ArrayList) but I cannot really remember the effects of it. You probably loose some of the features (such as lazy initialization) and possibly some performance.