IIRC an interface can actually extend multiple interfaces. So also the Session should be able to extend AutoCloseable and Runnable.
On 2011-12-16, at 13:48, Nigel Deakin wrote:
> On 15/12/2011 18:27, Nigel Deakin wrote:
>> On 29/09/2011 15:24, Nigel Deakin wrote:
>>> I'd like to raise this as a discussion topic rather than a concrete proposal.
>>>
>>> I've also logged this in JIRA
>>> http://java.net/jira/browse/JMS_SPEC-53
>>>
>>> My question is: should we change all the JMS interfaces that currently implement a close() method to implement the
>>> java.lang.AutoCloseable interface?
>>>
>>> This would affect Connection, Session, MessageConsumer, MessageProducer, QueueBrowser.
>>
>> This proposal received support and no objections when I raised it some time ago.
>>
>> I've been looking at this in a bit more detail.
>>
>> Making Connection, MessageConsumer, MessageProducer, QueueBrowser extend AutoCloseable seems straightforward.
>>
>> However there's a problem with Session. This already extends Runnable, so I can't make it extend AutoCloseable. (I can't
>> think of an obvious way around this, but if I've missed something obvious please let me know)
>>
>> This suggests two options:
>>
>> 1. Leave Session unchanged and make all the other interfaces extend AutoCloseable
>>
>> 2. Option (1) is confusing and inconsistent to users. It's better to simply make Connection extend AutoCloseable and
>> leave the other interfaces unchanged. In practice the only object that actually needs closing in practice is COnnection
>> anyway.
>>
>> Any preferences? I'm inclined towards (2)...
>
> I've now updated the javadocs and the draft spec with details of this new feature (these changes are additive, so those
> docs include other changes).
>
> The updated Javadocs are here:
> http://java.net/projects/jms-spec/sources/repository/content/jms2.0/target/jms-2.0-javadoc.jar
> (See the small change to Connection)
>
> The updated draft spec is here:
> http://java.net/projects/jms-spec/sources/repository/content/jms2.0/specification/word/JMS20.pdf
> (all changes are highlighted clearly with changebars, but the only place I've changed is 4.3.5 "Closing a Connection",
> the example in section 9.1.3. Creating a Connection", and section 11.5.3 "Automatically closing a connection", which is
> just a change log)
>
> I've only made Connection extend AutoCloseable. As mentioned above, I couldn't change Session since this already extends
> Runnable. Although I could have changed MessageProducer, MessageConsumer and QueueBrowser I decided to leave these
> unchanged since I thought it better to have Connection as the special case which does support try-with-resources (since
> this is the only object that actually needs closing) rather than have Session as the special case which does not. (Note
> that MessagingContext, part of the proposed simplified API, already extends AutoCloseable)
>
> Nigel