Would an alternative be to have closer integration btw Tuscany and Axis2?
From the brief look I've had at the Tuscany code it seems like it really
has
its own completely separate SOAP engine. It builds the SOAP envelope on
its
own and passes that to Axis just for QOS and transport things.
So could an alternative be to create an Axis2 data binding for SDO's and
let
Axis2 handle the constructing of the SOAP envelope? That way Tuscany
wouldn't have to worry about all usual issues like rpc/enc, SOAP 1.1/1.2,
attachments, MTOM etc.
...ant
On 1/12/06, Raymond Feng <[EMAIL PROTECTED]> wrote:
I would like to start the disucssion on AXIS2 integration for Tuscany.
I started to prototype the AXIS2 support for Tuscany web service
binding.
Following the similar approach as we do for Axis 1.x, the key enabling
factor is the serialization/deserialization from SDO to AXIOM and vice
versa. Generally speaking, it's all about the transformations between
different XML bindings for the same data. Please see the attached the
diagram for some examples.
As the default data model for Tuscany, SDO DataObject is used to
represent
the input/output/fault message for web services. (Later on, it could be
pluggable.)
In Axis 1.x, the SOAP envelope is a DOM-based model.
Serialization: SDO --> DOM (SOAP)
Deserialization: DOM --> SDO
Due to some issues of the DOM support in the SDO 1.0 implementation, we
made some workarounds in the current code base. So the real path may
look
like this:
Serialization: SDO --> String --> SOAP
Deserialization: SOAP --> String --> SAX --> SDO
In Axis 2, SOAP messages are modeled using AXIOM (AXis Object Model)
which
is an XML object model working on StAX (Streaming API for XML) parsing
optimized for SOAP 1.1/1.2 Messages. The ideal path should be:
Serialization: SDO --> StAX --> SOAP (AXIOM)
Deserialization: SOAP (AXIOM) --> StAX --> SDO
The StAX support is not there yet in the current SDO implementation. So
I
took a hacky way and managed to make this path work with the Axis2
0.93driver for the outbound Web Service call.
Serialization: SDO --> AXIOM (by the special XMLSaveImpl which creates
AXIOM attributes/elements/text in a similar way as DOM)
Deserialization: AXIOM --> StAX --> StAX2SAXAdapter --> SAX --> SDO
Now it becomes desirable to have a set of flexible SDO2
serializer/deserializers (or XMLResource in the SDO/EMF term) as
follows:
SAX: Generate SAX events from DataObject and load DataObject from SAX
events
Stax: Implement StAX XMLStreamReader for a given DataObject and load
DataObject from XMLStreamReader (potentially can support lazy-loading of
DataObject?)
DOM: Create DOM tree from DataObject and load DataObject from DOM
IMHO, these utilities will not only benifit the SDO/Axis integration,
but
also the transformation between SDO and other models like JAXB and
XMLBeans.
Ideas? Opinions?
Thanks,
Raymond
