JAX_WX holders and in/out parameters support in SCA

[Liu, Jervis]

Hi, 

I have been reading relevant SCA specs, according to the spec, holders are not 
supported by SCA. I wonder, how in/out parameters can be done in SCA without 
holders? Lets say I have a wdsl like below:

.....
        <wsdl:message name="sayHi">
                <wsdl:part name="sayIn" element="x1:sayHi"/>
        </wsdl:message>
        <wsdl:message name="sayHiResponse">
                <wsdl:part name="sayIn" element="x1:sayHi"/>
        </wsdl:message>
        <wsdl:portType name="Greeter">
                <wsdl:operation name="sayHi">
                        <wsdl:input name="sayHiRequest" message="tns:sayHi"/>
                        <wsdl:output name="sayHiResponse" 
message="tns:sayHiResponse"/>
                </wsdl:operation>
        </wsdl:portType>
.....

In a JAX_WS compliant implementation, this wsdl will result in using a holder 
class as parameter for method sayHi. In Tuscany, what does the corresponding 
Java interface look like? And does Tuscany support in/out parameters?

Another question I would like to ask is that do we have a wsdltojava and 
javatowsdl tool in Tuscany?  If I take a WSDL-first approach, without such a 
tool, how can I make sure my Java interface that implements web service is 
actually compliant to the WSDL interface?

I am new to SCA, excuse my ignorance if I have misunderstood some SCA concepts.

Thanks,
Jervis Liu