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From Craig L Russell <Craig.Russ...@Sun.COM>
Subject Re: JDBC 4 (was: Was it just me?)
Date Tue, 01 Aug 2006 14:47:05 GMT
It's my fault. I read email recent-first and didn't notice Brett  
created -4 (hours earlier) which I duplicated with -5. But -6 is a  
different issue...

Imagine my surprise that we now have duplicates in our tiny JIRA repo!

Craig

On Jul 31, 2006, at 11:07 PM, Brett Porter wrote:

> Hmm, did we all create the same JIRA issue? :)
>
> I crated OPENJPA-4 at the same time as the other issue, but it seems
> -5 and -6 are both about the same thing.
>
> - Brett
>
> On 01/08/06, Craig L Russell <Craig.Russell@sun.com> wrote:
>> This definitely needs a JIRA issue. We should use the JIRA to track
>> our discussion of the issue, unless folks think it's better to use
>> our wiki. Is it set up yet?
>>
>> Craig
>>
>> On Jul 31, 2006, at 10:15 PM, Patrick Linskey wrote:
>>
>> Yes, OpenJPA implements Statement, ResultSet, Connection, and maybe a
>> couple other JDBC interfaces. See
>> org.apache.openjpa.lib.jdbc.Delegating*. We do this for a number of
>> reasons: to resolve database-specific bugs in a transparent  
>> fashion, to
>> provide logging, to handle reference counting, etc.
>>
>> The pressing issue is that we must provide implementations of all  
>> of the
>> methods in the various java.sql interfaces. The fact that we do not
>> implement the new JDBC4 methods is why OpenJPA won't currently  
>> compile
>> against JDK6. This is pretty easy to fix; take a look at
>> org.apache.openjpa.lib.jdbc.DelegatingStatement to see how we handled
>> this for JDBC3. Since we know that we never invoke the new  
>> methods, we
>> can happily throw unsupported operation exceptions for the new  
>> methods.
>>
>> However, these unsupported methods do provide a challenge. While Kodo
>> doesn't use any of these methods, our mechanism for implementing  
>> them is
>> limiting, in that users who obtain Connections from Kodo will not be
>> able to use the new JDBC3/JDBC4 methods in their own code.  
>> Ideally, we
>> should provide some means for people to designate to OpenJPA that it
>> should use a dynamic proxy to implement the unimplemented methods.  
>> This
>> shouldn't be the default behavior, as the dynamic proxy will add
>> overhead, but certainly could be desirable for some. I'll file an  
>> issue.
>> >
>> > -Patrick
>> >
>> > --
>> > Patrick Linskey
>> > BEA Systems, Inc.
>> >
>> >> -----Original Message-----
>> >> From: Craig.Russell@Sun.COM [mailto:Craig.Russell@Sun.COM]
>> >> Sent: Monday, July 31, 2006 10:02 PM
>> >> To: open-jpa-dev@incubator.apache.org
>> >> Subject: Re: JDBC 4 (was: Was it just me?)
>> >>
>> >> You can access earlier versions of jdbc to compile against
>> >> using special javac properties for library jars. But I don't
>> >> know how maven deals with this.
>> >>
>> >> What specific errors are you getting when compiling against  
>> jdbc 4?
>> >> I'm not aware of any additions that would make programs that
>> >> compile against jdbc 3 not compile against jdbc 4. You don't
>> >> *implement* any jdbc interfaces, do you?
>> >>
>> >> Craig
>> >>
>> >> On Jul 31, 2006, at 8:37 PM, Patrick Linskey wrote:
>> >>
>> >>>>>> BTW, you may be aware, but it doesn't compile on Java 6
>> >>>> due to the
>> >>>>>> JDBC interface changes. I'll add that to JIRA if its not
there
>> >>>>>> already.
>> >>>>>
>> >>>>> Yeah, we've had this problem in the past as well.
>> >>>> Historically, we've
>> >>>>> created special modified JDBC jars so that we can compile
>> >>>> on earlier
>> >>>>> VM versions. How is this type of problem typically handled
>> >>>> in Apache-land?
>> >>>>
>> >>>> Isn't this the other way around? If the additional methods are
>> >>>> implemented to make it compile on Java 6, it will continue to be
>> >>>> binary compatible with the earlier JDBC versions.
>> >>>
>> >>> Yes, that. Meant "so that we can run on earlier VM versions."
>> >>>
>> >>> So... how does Apache typically deal with this? The only
>> >> alternate to
>> >>> the way we've done things in the past is an approach that
>> >> uses dynamic
>> >>> proxies / auto-generated proxies / dynamically-modified classes.
>> >>>
>> >>> -Patrick
>> >>>
>> >>  
>> _____________________________________________________________________
>> >> _
>> >>> _
>> >>> Notice:  This email message, together with any attachments, may
>> >>> contain
>> >>> information  of  BEA Systems,  Inc.,  its subsidiaries  and
>> >>> affiliated
>> >>> entities,  that may be confidential,  proprietary,  copyrighted
>> >>> and/or
>> >>> legally privileged, and is intended solely for the use of the
>> >>> individual or entity named in this message. If you are not the
>> >>> intended recipient, and have received this message in error,  
>> please
>> >>> immediately return this by email and then delete it.
>> >>
>> >> Craig Russell
>> >> Architect, Sun Java Enterprise System http://java.sun.com/ 
>> products/
>> >> jdo
>> >> 408 276-5638 mailto:Craig.Russell@sun.com P.S. A good JDO? O,  
>> Gasp!
>> >>
>> >>
>> >  
>> _____________________________________________________________________ 
>> _
>> > _
>> > Notice:  This email message, together with any attachments, may
>> > contain
>> > information  of  BEA Systems,  Inc.,  its subsidiaries  and
>> > affiliated
>> > entities,  that may be confidential,  proprietary,  copyrighted
>> > and/or
>> > legally privileged, and is intended solely for the use of the
>> > individual
>> > or entity named in this message. If you are not the intended
>> > recipient,
>> > and have received this message in error, please immediately return
>> > this
>> > by email and then delete it.
>>
>> Craig Russell
>> Architect, Sun Java Enterprise System http://java.sun.com/products/ 
>> jdo
>> 408 276-5638 mailto:Craig.Russell@sun.com
>> P.S. A good JDO? O, Gasp!
>>
>>
>>
>>
>
>
> -- 
> Apache Maven - http://maven.apache.org
> "Better Builds with Maven" book - http://library.mergere.com/

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!


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