I think either way works...
On 9/20/2011 9:21 AM, Nigel Deakin wrote:
> OK, let's try again :-)
>
> Currently we have two methods on Session which return a TopicSubscriber:
>
> TopicSubscriber createDurableSubscriber(Topic topic, java.lang.String
> name)
>
> TopicSubscriber createDurableSubscriber(Topic topic, java.lang.String
> name, java.lang.String messageSelector, boolean noLocal)
>
> To allow us to deprecate and propose for removal all the
> domain-specific classes (apart from Queue and Topic), we need to
> provide new versions of this method which return a MessageConsumer.
>
> We can't simply add new methods with the same name which return a
> MessageConsumer since the compiler would consider these duplicate
> methods.
>
> Reza suggests we add:
>
> Option 1
> --------
>
> MessageConsumer createConsumer(Topic topic, java.lang.String name)
>
> MessageConsumer createConsumer(Topic topic, java.lang.String name,
> java.lang.String messageSelector, boolean noLocal)
>
> However there's potential confusion between the first of those methods
> and the existing method to create an ordinary consumer with a message
> selector:
>
> MessageConsumer createConsumer(Destination destination,
> java.lang.String messageSelector)
>
> The compiler would allow it, but if the user tried to create a durable
> subscription using a variable which was really a Topic but which was
> declared as Destination then the wrong method would be called.
>
> We could either live with this, or we could use:
>
> Option 2
> --------
>
> MessageConsumer createDurableConsumer(Topic topic, java.lang.String name)
>
> MessageConsumer createDurableConsumer(Topic topic, java.lang.String
> name, java.lang.String messageSelector, boolean noLocal)
>
> Any preferences?
>
> Nigel
>
> On 19/09/2011 18:43, reza_rahman_at_lycos.com wrote:
>> +1. I think createConsumer() that takes a Topic (as opposed to a
>> generic JMS Destination) and a durable subscriber
>> name as argument might be fine.
>>
>>
>> Sep 19, 2011 12:56:07 PM, jsr343-experts_at_jms-spec.java.net wrote:
>>
>> On 19/09/2011 13:20, Ruediger zu Dohna wrote:
>>> Nigel,
>>>
>>> wouldn't existing code need to do a downcast from MessageConsumer to
>>> TopicSubscriber?
>>
>> Er, yes. So it would! I wasn't thinking properly...
>>
>> I was trying to avoid users having to change their code. Perhaps we
>> need to add a new method and deprecate the old
>> one.
>>
>> Thanks,
>>
>> Nigel
>>
>>>
>>> On 19.09.2011 13:40, Nigel Deakin wrote:
>>>> On 16/09/2011 19:58, reza_rahman_at_lycos.com wrote:
>>>>> +1. However, it would not be 100% backwards compatible, would it?
>>>>>
>>>> What kind of compatibility would this break? Existing application
>>>> code would not need to be changed.
>>>>
>>>> Nigel
>>>>
>>>>
>>>>> Sep 16, 2011 02:35:46 PM, jsr343-experts_at_jms-spec.java.net
>>>>> <mailto:jsr343-experts_at_jms-spec.java.net> wrote:
>>>>>
>>>>> I have logged the following JIRA issue:
>>>>> http://java.net/jira/browse/JMS_SPEC-51
>>>>>
>>>>> Here is the description, which I think is self-explanatory (I
>>>>> originally raised this as part of JMS_SPEC-47,
>>>>> but I am now separating it out to a separate trackable issue).
>>>>>
>>>>> There were no objections when I first suggested this, but if
>>>>> anyone has any comments please make them now.
>>>>>
>>>>> ---------------------- In JMS 1.1 the method
>>>>> Session.createDurableSubscriber() returns a TopicSubscriber, not a
>>>>> MessageConsumer.
>>>>>
>>>>> This is the only "domain-independent" method in the whole JMS 1.1
>>>>> API which depends on a "domain-specific"
>>>>> interface. This dependency prevents the "domain-specific"
>>>>> interfaces being removed from JMS as proposed in
>>>>> JMS_SPEC-47
>>>>>
>>>>> It is therefore proposed to modify this method to return a
>>>>> MessageConsumer. Since this is a supertype of
>>>>> TopicSubscriber it should not break existing applications.
>>>>> ----------------------
>>>>>
>>>>>
>>>>> Nigel
>>>>>
>>>>>
>
>
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