[hibernate-dev] Stream result change proposal

[andrea boriero]

it sounds reasonable to me

On 7 June 2016 at 10:57, Vlad Mihalcea <mihalcea.vlad at gmail.com> wrote:

> To get a picture of why we need this, consider the following example from
> the docs:
>
> Stream<Object[]> persons = session.createQuery(
>    "select p " +
>    "from Person p " +
>    "where p.name like :name" )
> .setParameter( "name", "J%" )
> .stream();
>
> Map<Phone, List<Call>> callRegistry = persons
>    .map( row -> Person.class.cast( row[0] ) )
>    .flatMap( person -> person.getPhones().stream() )
>    .flatMap( phone -> phone.getCalls().stream() )
>    .collect(Collectors.groupingBy(Call::getPhone));
>
>
> The .map( row -> Person.class.cast( row[0] ) ) call should be avoided and
> we should return a Stream<Person> in this case.
>
> Vlad
>
> On Tue, Jun 7, 2016 at 12:50 PM, Vlad Mihalcea <mihalcea.vlad at gmail.com>
> wrote:
>
> > Hi,
> >
> > While writing documentation for the new 5.2 Query.stream() API, I
> realized
> > that we don't return a Stream<T>, but a Stream<Object[]> which could
> > confuse users.
> > This is because ScrollableResultsImpl does something like this:
> >
> > if ( result != null && result.getClass().isArray() ) {
> >    currentRow = (Object[]) result;
> > }
> > else {
> >    currentRow = new Object[] {result};
> > }
> >
> > The result is the actual entity that we queries, while the currentRow is
> an Object[].
> >
> > I think we might want to change the stream result so that we return the
> result for each available entry.
> >
> > Vlad
> >
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