I would not say that this is "very vendor-specific". Certainly the method
leaves a lot of freedom for the provider in terms of implementation, but
honestly that is not any different from most other aspects of the JPA
APIs. Provider-X might define a far more efficient/performant
implementation of any JPA API method as opposed to Provider-Y. I do not
see how this one is any different.
On Fri, May 5, 2017 at 1:51 PM Linda DeMichiel <linda.demichiel_at_oracle.com>
wrote:
> Hi all,
>
> To me this still sounds very vendor-specific at this point.
>
> Wouldn't it be better to just allow vendors to provide such
> functionality through the loophole that we currently have -- i.e.,
> by an unwrap of the Query object into the vendor-specific one.
>
> Then once we can agree on some more specific semantics here this
> can be standardized in a future release.
>
> We might want to add an unwrap to TypedQuery as well, but that
> is trivial enough.
>
> -Linda
>
>
> On 5/5/17, 11:40 AM, Lukas Jungmann wrote:
> > Hi,
> >
> >
> > On 5/4/17 11:35 PM, Linda DeMichiel wrote:
> >> Hi,
> >>
> >> If the value is mostly in the provider-specific add-ons, then I
> >> think it would be better to wait and standardize in a later
> >> release.
> >>
> >> What did you have in mind here?
> >
> > basically provide an API returning a Stream which is not constrained by
> > some specific characteristics (as Oliver pointed users expectation may
> > vary here) while still having ability to constrain them, or maybe better
> > - influence the behaviour of the returned stream through provider
> > specific QueryHints.
> >
> > as for the name of the method - I've chosen 'getResultStream' to be
> > consistent with existing methods; but I don't mind if I'm over voted
> > here as long as we have sth like this availiable
> >
> > thanks,
> > --lukas
> >>
> >> -Linda
> >>
> >>
> >> On 5/4/17, 1:01 PM, Lukas Jungmann wrote:
> >>> Hi,
> >>>
> >>> another change I'd like to propose is an addition of
> >>> getResultStream:Stream method to javax.persistence.Query/TypedQuery
> >>> interfaces with following javadoc and provided with default
> >>> implementation:
> >>>
> >>> javax.persistence.Query:
> >>>
> >>> / /**//
> >>> // * Execute a SELECT query and return the query results//
> >>> // * as an untyped <code>java.util.Stream</code>.//
> >>> // * By default this method delegates to
> >>> <code>getResultList().stream()</code>,//
> >>> // * however persistence provider may choose to override this
> >>> method//
> >>> // * to provide additional capabilities.//
> >>> // *//
> >>> // * @return a stream of the results//
> >>> // * @throws IllegalStateException if called for a Java//
> >>> // * Persistence query language UPDATE or DELETE
> statement//
> >>> // * @throws QueryTimeoutException if the query execution exceeds//
> >>> // * the query timeout value set and only the statement
> is//
> >>> // * rolled back//
> >>> // * @throws TransactionRequiredException if a lock mode other
> >>> than//
> >>> // * <code>NONE</code> has been set and there is no
> >>> transaction//
> >>> // * or the persistence context has not been joined to the
> >>> transaction//
> >>> // * @throws PessimisticLockException if pessimistic locking//
> >>> // * fails and the transaction is rolled back//
> >>> // * @throws LockTimeoutException if pessimistic locking//
> >>> // * fails and only the statement is rolled back//
> >>> // * @throws PersistenceException if the query execution exceeds //
> >>> // * the query timeout value set and the transaction //
> >>> // * is rolled back //
> >>> // * @see Stream//
> >>> // * @see #getResultList()//
> >>> // * @since 2.2//
> >>> // *///
> >>> // default Stream getResultStream() {//
> >>> // return getResultList().stream();//
> >>> // }/
> >>>
> >>> similarly to javax.persistence.TypedQuery:
> >>>
> >>> / /**//
> >>> // * Execute a SELECT query and return the query results//
> >>> // * as a typed <code>java.util.Stream</code>.//
> >>> // * By default this method delegates to
> >>> <code>getResultList().stream()</code>,//
> >>> // * however persistence provider may choose to override this
> >>> method//
> >>> // * to provide additional capabilities.//
> >>> // *//
> >>> // * @return a stream of the results//
> >>> // * @throws IllegalStateException if called for a Java//
> >>> // * Persistence query language UPDATE or DELETE
> statement//
> >>> // * @throws QueryTimeoutException if the query execution exceeds//
> >>> // * the query timeout value set and only the statement
> is//
> >>> // * rolled back//
> >>> // * @throws TransactionRequiredException if a lock mode other
> >>> than//
> >>> // * <code>NONE</code> has been set and there is no
> >>> transaction//
> >>> // * or the persistence context has not been joined to the
> >>> transaction//
> >>> // * @throws PessimisticLockException if pessimistic locking//
> >>> // * fails and the transaction is rolled back//
> >>> // * @throws LockTimeoutException if pessimistic locking//
> >>> // * fails and only the statement is rolled back//
> >>> // * @throws PersistenceException if the query execution exceeds //
> >>> // * the query timeout value set and the transaction //
> >>> // * is rolled back //
> >>> // * @see Stream//
> >>> // * @see #getResultList()//
> >>> // * @since 2.2//
> >>> // *///
> >>> // default Stream<X> getResultStream() {//
> >>> // return getResultList().stream();//
> >>> // }/
> >>>
> >>> Do you think this is OK or does it give providers to big freedom?
> >>>
> >>> Thank you,
> >>> --lukas
> >>>
> >
>