[hibernate-dev] Backward compatibility with hibernate 4.1.9

[Steve Ebersole]

Exactly.  You are relying, externally, on an internal detail of 
Hibernate.  These are connections controlled by Hibernate.   Plus, as 
Sanne already mentioned, you are talking about behavior across 
different major versions.


pass it Connection.class.  Or, yes, you can also pass it a more 
concrete Connection class.  But the Hibernate Connection proxy 
understands:

unwrap ( Connection.class )

as a request to "unwrap" itself by returning the underlying JDBC 
connection


On Fri 15 Feb 2013 07:41:49 AM CST, amit shah wrote:
> I didn't understand the reason why you say that it is not a backward
> compatibility problem. Isn't creating proxies a internal logic of
> hibernate?
>
> Also I didn't get the unwrap() solution? What parameter should the
> client code pass to the unwrap() method ? The driver class name?
>
> As a workaround - Is there a hibernate configuration property to
> inform hibernate to not proxy jdbc classes?
>
> Thank you for the quick responses.
>
>
> On Fri, Feb 15, 2013 at 6:44 PM, Steve Ebersole <steve at hibernate.org
> <mailto:steve at hibernate.org>> wrote:
>
>     If you want the un-proxied version of the JBDC Connection, then
>     unwrap() it.  That is the standard pattern for dealing with JDBC
>     objects.
>
>     And no, this is not a backwards compatibility problem.
>
>
>     On Fri 15 Feb 2013 06:52:33 AM CST, amit shah wrote:
>
>         I think the defect description was not clear probably. The
>         issue is
>         not related to backward compatibility of hibernate with other
>         frameworks (spring in this case). It is with hibernate 4.1.9
>         vs 3.6.0.
>
>         Hibernate 3.6.0 threw checked exceptions (SQLException) while
>         4.1.9
>         throws an unchecked exception (SQLGrammerException).
>
>
>         On Fri, Feb 15, 2013 at 5:28 PM, Sanne Grinovero
>         <sanne at hibernate.org <mailto:sanne at hibernate.org>
>         <mailto:sanne at hibernate.org <mailto:sanne at hibernate.org>>> wrote:
>
>             Hi Amit,
>             please use the developer list for such concerns, which
>         I've added
>             in CC.
>
>             Personally I don't think your issue is valid, but I'll
>         leave that to
>             the other team members to decide.
>             We never promised backwards compatibility with other
>         frameworks when
>             upgrading from Hibernate 3 to 4, it is likely that you
>         will need to
>             make some adjustments in configurations; also I'm not a
>         Spring expert
>             but from what you describe it looks to me it's not a good
>         idea to use
>             the "spring jdbc template" as JDBC and Hibernate are two
>         different
>             things.
>
>             Sanne
>
>             On 15 February 2013 11:41, amit shah <amits.84 at gmail.com
>         <mailto:amits.84 at gmail.com>
>             <mailto:amits.84 at gmail.com <mailto:amits.84 at gmail.com>>>
>         wrote:
>             > Hello Steve/Sanne,
>             >                While upgrading to hibernate 4.1.9 from
>         3.6.0 I
>             am facing an
>             > blocking issue for which I would appreciate if you can
>         provide
>             your inputs.
>             > The issue was logged on jira forum but it didn't get much
>             attention. I will
>             > paste it here once.  Kindly let me know your thoughts.
>             >
>             >
>             > Description
>             >
>             > I upgraded my project with hibernate 4.1.9 and spring
>         3.2.1 and
>             noticed that
>             > hibernate throws RuntimeExceptions instead of checked
>         exception
>             in the
>             > earlier version (3.6.0 final was the one we used
>         earlier). The
>             code use case
>             > is as below.
>             >
>             > We use spring jdbc template for executing jdbc queries
>         and the
>             application
>             > is configured to use JPA (JPATransactionManager and
>         JPADialect)
>             for mapped
>             > entities. When executing a query which could throw a
>         exception
>             for e.g. a
>             > select query on a table that does not exist, hibernate now
>             proxies the jdbc
>             > statements and throws a SQLGrammerException (extends
>             RuntimeException)
>             > instead of a checked exception - SQLException.
>             >
>             > Since spring catch's SQLException, the code no longer
>         executes
>             the catch
>             > block and fails with an exception.
>             >
>             > Attached a sample java program to reproduce the issue.
>         Please
>             execute the
>             > main method of the ExceptionHandlingTask class. It
>         starts a spring
>             > transaction and executes a query on a non existing table.
>             >
>             > Spring and hibernate jars must be included in the classpath.
>             >
>             > Thank you,
>             > Amit.
>
>
>