[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-6865) PessimisticLockException should be thrown when pessimistic read and write locking strategies fail

[Steve Ebersole (JIRA)]

    [ http://opensource.atlassian.com/projects/hibernate/browse/HHH-6865?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=44485#comment-44485 ] 

Steve Ebersole commented on HHH-6865:
-------------------------------------

I went a slightly different direction than the pull request, in taking this opportunity to fix an underlying problem (imo).  Basically, {{org.hibernate.PessimisticLockException}} was being used in 2 completely different ways:
# as a jdbc-level exception (converted from {{SQLException}})
# as a higher-level exception, thrown from locking strategies

In the first case it represents a low-level error coming back from the database.  In that latter, its an error relating to an entity.

Essentially I wanted to have {{LockingStrategy}} throw a unified hierarchy of these "high level lock exceptions".  To that end, I introduced {{org.hibernate.dialect.lock.LockingStrategyException}} with 2 subclassess: {{org.hibernate.dialect.lock.OptimisticEntityLockException}} and {{org.hibernate.dialect.lock.PessimisticEntityLockException}}.  I would really have liked to just drop {{org.hibernate.OptimisticLockException}}, but opted for deprecating it at the moment since it is in the public package namespace (org.hibernate).  We can clean that up later.

Additionally, I would like to move the {{org.hibernate.dialect.lock}} package outside of the {{org.hibernate.dialect}} package.  Maybe {{org.hibernate.lock}} or {{org.hibernate.engine.lock}}.  Not critical, but nice to have at some point.

> PessimisticLockException should be thrown when pessimistic read and write locking strategies fail
> -------------------------------------------------------------------------------------------------
>
>                 Key: HHH-6865
>                 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-6865
>             Project: Hibernate Core
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 4.0.0.CR6
>            Reporter: Gail Badner
>            Assignee: Steve Ebersole
>             Fix For: 4.0.0.next
>
>          Time Spent: 3h 46m
>
> In some cases, when a pessimistic read/write locking strategy fails with SQLException, Hibernate converts the SQLException to a org.hibernate.JDBCException, but does not wrap the JDBCException in a org.hibernate.PessimisticLockException.
> This affects:
> PessimisticReadSelectLockingStrategy.lock(...)
> PessimisticReadUpdateLockingStrategy.lock(...)
> PessimisticWriteSelectLockingStrategy.lock(...)
> PessimisticWriteUpdateLockingStrategy.lock(...)
> These methods specifically catch SQLException, convert it to a org.hibernate.JDBCException, and wrap in a org.hibernate.PessimisticLockException.
> If Hibernate does the conversion immediately when the statement fails and throws JDBCException, then lock(...) does not have the opportunity to catch it and wrap it in a org.hibernate.PessimisticLockException.
> This issue is reproduced in LockTest failures on Oracle.  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira