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Re: MappedSuperClass annotation

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On 1/27/12 7:24 PM, Lew wrote:
> Daniel Pitts wrote:
>> Lew wrote:
>>> Pidi wrote:
>>>> If an abstract class inherits from an abstract superclass annotated
>>>> with
>>>> @MappedSuperclass, it inherits the annotation too or if I want both
>>>> annotated
>>>> I have to replicate the annotation?
>>>>
>>>> Ex:
>>>> @MappedSuperclass
>>>> public abstract Class1 {
>>>> ...
>>>> }
>>>>
>>>> @MappedSuperclass <-- I have to declare it or it's implicit?
>>>> public abstract Class2 extends Class1{
>>>> ...
>>>> }
>>>
>>> You have to declare it. Annotations do not inherit.
>> True, and that annotation specifically needs to be declared everywhere
>> you
>> want the effect.
>>
>> In general though, it is up to the framework which utilizes the
>> annotations to
>> decide if they want to climb up the inheritance or not.
>
> Good point, but I couldn't come up with an example that does, and
> certainly none for JPA.
>
> This is at least hinted if not evident from the documentation, for example:
> <http://docs.oracle.com/javaee/6/tutorial/doc/bnbqn.html>
> in which the very introduction of entities shows the need to repeat the
> '@Entity' annotations at each level of inheritance.
>
> That said, the need for multiple levels of inherited '@MappedSuperclass'
> annotated types should be vanishingly rare. There's a very, very good
> chance that the OP should *STOP* what they're doing and reconsider, then
> get rid of the idea. I cannot even think of a scenario where it would
> help. It goes firmly against the intended purpose of that annotation.
>
I have needed multiple levels of inheritance for different feature 
combinations on some entities. Not often, but it does happen in real 
world use-cases.

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MappedSuperClass annotation Pidi <lamia@mail.com> - 2012-01-27 17:05 +0100
  Re: MappedSuperClass annotation Lew <noone@lewscanon.com> - 2012-01-27 10:50 -0800
    Re: MappedSuperClass annotation Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-01-27 12:50 -0800
      Re: MappedSuperClass annotation Lew <noone@lewscanon.com> - 2012-01-27 19:24 -0800
        Re: MappedSuperClass annotation Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-01-29 08:53 -0800
          Re: MappedSuperClass annotation Lew <noone@lewscanon.com> - 2012-01-29 10:05 -0800
            Re: MappedSuperClass annotation Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-01-29 22:45 -0800
              Re: MappedSuperClass annotation Lew <noone@lewscanon.com> - 2012-01-30 10:06 -0800
                Re: MappedSuperClass annotation Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-31 06:52 -0400
                Re: MappedSuperClass annotation Lew <noone@lewscanon.com> - 2012-01-31 11:07 -0800
      Re: MappedSuperClass annotation Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-28 12:02 -0400

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