db-jdo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Matthew T. Adams" <matthew.ad...@xcalia.com>
Subject RE: Persistent Interfaces in JDO 2.0
Date Thu, 20 Jul 2006 20:09:07 GMT
>-----Original Message-----
>From: Craig.Russell@Sun.COM [mailto:Craig.Russell@Sun.COM] 
>Sent: Thursday, July 20, 2006 8:59 AM
>To: Robin M. Roos
>Cc: JDO Expert Group; Apache JDO project
>Subject: Re: Persistent Interfaces in JDO 2.0
>
>> [I actually believe the "property" element in this context, within
>> "implements" should be a simpler XML element which maps the name
>> from the interface to a fully defined property in this
>> persistence-capable, but the DTD reuses the same property element
>> here.  This potentially stops one class from implementing two
>> interfaces and mapping the "description" property of each of them
>> to the same persistent field.  It would have to define the field
>> twice if "description" was an (abstract) property in both
>> interfaces.]
>
>Java has this same restriction. A class that implements multiple  
>interfaces must have identical implementations for methods from the  
>multiple interfaces that have the same signature. There's no way to  
>disambiguate the methods of one interface from the others. Do other  
>languages allow different behavior?
>>
C# (and potentially other .NET-compliant languages), actually.  It's a
concept called "explicit interface implementation", I believe.  Yes:
http://msdn2.microsoft.com/en-us/library/ms173157.aspx

--matthew



Mime
View raw message