Re: EntityManager.clear() semantics

[Craig L Russell]

Hi Kevin,

I agree with your analysis.





Craig

On Jan 30, 2007, at 2:32 PM, Kevin Sutter wrote:

I would also like to see a CTS test made for this case. Do we have a channel through BEA or IBM for requests for CTS test cases? Another recent example is the EntityManager.getDelegate behavior which surely should be a candidate for a CTS test.

Hi,
We've noticed that when EntityManager.clear() is invoked, an implicit


/**
* Clear the persistence context, causing all managed
* entities to become detached. Changes made to entities that
* have not been flushed to the database will not be
* persisted.
*/
public void clear();

This indicates that Entities that have not been flushed will not be

before the clear, then they can call the flush() method before calling

choice.




was invoked..."

Our current processing for clear() eventually gets to this code:

   public void detachAll(OpCallbacks call) {
       beginOperation(true);
       try {
           if ((_flags & FLAG_FLUSH_REQUIRED) != 0)
               flush();
           detachAllInternal(call);
       } catch (OpenJPAException ke) {
           throw ke;
       } catch (RuntimeException re) {
           throw new GeneralException(re);
       } finally {
           endOperation();
       }
   }


doing this flush() operation.  Any disagreement?

Thanks,
Kevin

flush() is performed. Although the spec is cloudy in this area, I don't think this processing is correct. The javadoc is as follows for clear(): persisted. Thus, I would say this implies that we should not be doing an implicit flush. If the application wanted their Entities to be flushed clear(). We shouldn't be doing this for them because then they have no The Pro EJB3 Java Persistence API book has similar wording on pages 138-139: "..In many respects [clear] is semantically equivalent to a transaction rollback. All entity instances managed by the persistence context become detached with their state left exactly as it was when the clear() operation Basically, if we have dirtied the Persistence Context, then do a flush() followed by the detachAllInternal(). I don't think the clear() should be

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

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