You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@tuscany.apache.org by Scott Kurz <sc...@gmail.com> on 2009/04/30 16:39:19 UTC
why do we use JAXB declaredType unmarshalling instead of global
element unmarshalling?
I was asking this question wrt, e.g. OMElement2JAXB.
If we have WS-I compliant WSDL then we always have a global element.
Is it because we're counting on this code to, say, deserialize
component property values expressed in SCDL documents?
Was planning on suggesting global elem unmarshalling as an improvement
but first thought it was worth understanding why we do this today.
Thanks,
Scott
Re: why do we use JAXB declaredType unmarshalling instead of global
element unmarshalling?
Posted by Scott Kurz <sc...@gmail.com>.
On Thu, Apr 30, 2009 at 12:51 PM, Raymond Feng <en...@gmail.com> wrote:
> More comments inline.
....
> For example, we have a java method A talking to B:
>
> A:
> void updateAddress(String customerId, AddressSDO address)
>
> B:
> @RequestWrapper(...)
> @ResponseWrapper(...)
> void updateAddress(String customerId, AddressJAXB address)
>
> We don't have a SDO wrapper, so we convert AddressSDO to AddressJAXB.
Hmm.. for this case, I would think we would want to generate an SDO
wrapper instead. (I'm thinking more along the lines of registering a
type/elem dynamic-SDO-style, not necessarily generating a static SDO
wrapper).
Anyway, this is getting a bit off the point of my original question,
which you definitely answered.
I'm going to open a JIRA at least for now as I think the global elem
unmarshalling would be useful, though I'm not so sure how it could be
added to the existing set of JAXB-related transformers (i.e. how would
we pick which unmarshalling style to choose?).
Thanks,
Scott
Re: why do we use JAXB declaredType unmarshalling instead of global element unmarshalling?
Posted by Raymond Feng <en...@gmail.com>.
More comments inline.
--------------------------------------------------
From: "Scott Kurz" <sc...@gmail.com>
Sent: Thursday, April 30, 2009 9:12 AM
To: <de...@tuscany.apache.org>
Subject: Re: why do we use JAXB declaredType unmarshalling instead of global
element unmarshalling?
> Thanks. Replied...
>
> On Thu, Apr 30, 2009 at 11:43 AM, Raymond Feng <en...@gmail.com>
> wrote:
>> There are a few thoughts behind:
>>
>> 1) In SCA, JAXB objects are not always used for doc-lit wrapper style Web
>> Service. There are cases that the transformer convert XML data into a
>> JAXB
>> object without a global element. For example, the XSD only contains type
>> definitions.
>
> Is the example I mentioned, the instantiation of properties in a Java
> component impl, something like what you had in mind here? So to do
> unmarshalling by global elem we would need the user to add xsi:type
> hints in addition? Are there other examples?
Yes, we also need to support properties using XSD complex types. There are
two flavors to
define the value:
* Use a global element
* Use the local element with xsi:type
>
>> 2) We also deal with data transformation from non-wrapper to wrapper JAXB
>> which child elements from the source operation are converted to child
>> objects under the JAXB wrapper.
>
> Hmm... I'd like to understand this more. Could you please explain the
> example in more detail?
For example, we have a java method A talking to B:
A:
void updateAddress(String customerId, AddressSDO address)
B:
@RequestWrapper(...)
@ResponseWrapper(...)
void updateAddress(String customerId, AddressJAXB address)
We don't have a SDO wrapper, so we convert AddressSDO to AddressJAXB.
>
>> 3) We treat POJOs as JAXB objects. I cannot remember if the
>> global-element
>> based unmarshalling works for them.
>
> Not sure how this would be a problem unless this is a special case of
> 1). If we had a POJO on a wrapper-style Java, we'd typically end up
> generating a wrapper elem and deserializing to the wrapper, so I'm not
> seeing what there would be to worry about.
>
>> What's the benefit to use JAXB unmarshalling without a declared type?
>
> One motive is I'm trying to use an IBM-proprietary parser with
> optimized support for unmarshalling into a global element.
>
> However, besides that I'd also just like to understand, in order to
> understand, say, dynamic SDO. I'm trying to grasp for what
> SDO-in-SCA paths we would not have a global element registered.
>
> Thanks,
> Scott
Re: why do we use JAXB declaredType unmarshalling instead of global
element unmarshalling?
Posted by Scott Kurz <sc...@gmail.com>.
Thanks. Replied...
On Thu, Apr 30, 2009 at 11:43 AM, Raymond Feng <en...@gmail.com> wrote:
> There are a few thoughts behind:
>
> 1) In SCA, JAXB objects are not always used for doc-lit wrapper style Web
> Service. There are cases that the transformer convert XML data into a JAXB
> object without a global element. For example, the XSD only contains type
> definitions.
Is the example I mentioned, the instantiation of properties in a Java
component impl, something like what you had in mind here? So to do
unmarshalling by global elem we would need the user to add xsi:type
hints in addition? Are there other examples?
> 2) We also deal with data transformation from non-wrapper to wrapper JAXB
> which child elements from the source operation are converted to child
> objects under the JAXB wrapper.
Hmm... I'd like to understand this more. Could you please explain the
example in more detail?
> 3) We treat POJOs as JAXB objects. I cannot remember if the global-element
> based unmarshalling works for them.
Not sure how this would be a problem unless this is a special case of
1). If we had a POJO on a wrapper-style Java, we'd typically end up
generating a wrapper elem and deserializing to the wrapper, so I'm not
seeing what there would be to worry about.
> What's the benefit to use JAXB unmarshalling without a declared type?
One motive is I'm trying to use an IBM-proprietary parser with
optimized support for unmarshalling into a global element.
However, besides that I'd also just like to understand, in order to
understand, say, dynamic SDO. I'm trying to grasp for what
SDO-in-SCA paths we would not have a global element registered.
Thanks,
Scott
Re: why do we use JAXB declaredType unmarshalling instead of global element unmarshalling?
Posted by Raymond Feng <en...@gmail.com>.
There are a few thoughts behind:
1) In SCA, JAXB objects are not always used for doc-lit wrapper style Web
Service. There are cases that the transformer convert XML data into a JAXB
object without a global element. For example, the XSD only contains type
definitions.
2) We also deal with data transformation from non-wrapper to wrapper JAXB
which child elements from the source operation are converted to child
objects under the JAXB wrapper.
3) We treat POJOs as JAXB objects. I cannot remember if the global-element
based unmarshalling works for them.
What's the benefit to use JAXB unmarshalling without a declared type?
Thanks,
Raymond
--------------------------------------------------
From: "Scott Kurz" <sc...@gmail.com>
Sent: Thursday, April 30, 2009 7:39 AM
To: <de...@tuscany.apache.org>
Subject: why do we use JAXB declaredType unmarshalling instead of global
element unmarshalling?
> I was asking this question wrt, e.g. OMElement2JAXB.
>
> If we have WS-I compliant WSDL then we always have a global element.
>
> Is it because we're counting on this code to, say, deserialize
> component property values expressed in SCDL documents?
>
> Was planning on suggesting global elem unmarshalling as an improvement
> but first thought it was worth understanding why we do this today.
>
> Thanks,
> Scott