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From Apache Wiki <wikidi...@apache.org>
Subject [Jdo Wiki] Update of "Java5FeaturesAndJdo" by CraigRussell
Date Mon, 21 Nov 2005 17:42:46 GMT
Dear Wiki user,

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The following page has been changed by CraigRussell:
http://wiki.apache.org/jdo/Java5FeaturesAndJdo

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   * generics with wildcards as persistent field types...
  Generic wildcards allow the user to bound the types of persistent collection elements, or
map keys and values. For example, if we know that a {{{Set}}} can only contain {{{Number}}}
elements, we might declare it as a {{{Set<? extends Number> skills;}}}. Mapping this
persistent field to the datastore is similar to the issue of mapping a field of a superclass
to the datastore, e.g. {{{Number skill;}}}. And it is similar to mapping {{{Set<Number>}}}.
We believe that as far as JDO is concerned, the implementation can consider {{{Set<? extends
Number>}}} exactly as {{{Set<Number>}}}.
   * fields of type identifier type ...
- The only implementation class for type identifiers is Class, which cannot be persistent.
We plan to wait until a use-case is developed. 
+ The only implementation class for type identifiers is Class, which cannot be persistent.
I (clr) propose to wait until a use-case is developed. 
   * generics arrays ...
+ This seems to apply only to methods of generic classes and not to persistent behavior. I
(clr) propose to wait until a use-case is developed.
   * as persistence-capable classes ...
- This usage is not well-defined. It seems that most uses would involve some kind of wrapper
or holder that was type-specific. We plan to wait until a use-case is developed.
+ This usage is not well-defined. I (clr) think that most uses would involve some kind of
wrapper or holder that was type-specific. I (clr) propose to wait until a use-case is developed.
  
  = Enums =
  

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