The Apache WSIF promise of completely dynamic invocation has not been
completed yet because of this requirement to pregenerate the complex type
classes. When WSIF was originally donated to Apache it used JROM
(http://www.alphaworks.ibm.com/tech/jrom) but as thats not open source it
had to be removed from WSIF. It is possible to use JROM but the WSIF
provider need to be capable of doing this, and currently only the WSIF AXIS
provider is. Work is still going on to resolve this problem.
...ant
Anthony Elder
[EMAIL PROTECTED]
Web Services Development
IBM UK Laboratories, Hursley Park
(+44) 01962 818320, x248320, MP208.
Anuj Agrawal <[EMAIL PROTECTED]> on 01/04/2003 20:44:05
Please respond to [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
cc:
Subject: Re: Dynamic Invoker (was Re: SOAP samples)
Ok. That's the kind of info i was looking for. :) I'm surprised that
user-defined schema types will need to be generated, but maybe i
shouldn't be surprised. The alternative to that is to do what the
DynamicInvoker does.
Oh well.. back to the mines.
Anuj.
--- Nirmal Mukhi <[EMAIL PROTECTED]> wrote:
> Using the dynamic API directly, you do not need to generate any
> stubs. The
> only thing you need to have is java equivalents of all the user
> defined
> schema types used by the web service (these can be generated using
> WSDL2Java). This is demonstrated in all the dynamic clients for the
> samples. If your web service doesn't have user defined types, you
> don't
> generate anything.
>
> If you use the stub API, in addition to having the java types, you
> need to
> generate a stub interface.
>
> Anuj Agrawal <[EMAIL PROTECTED]>
> This was good information - thanks Nirmal! By 'truly dynamic' i
> meant
> that there is no need to *generate* any stubs etc.
>
> My particular scenario is that currently there is a need to connect
> to
> one web service. However, we forsee needing to connect to multiple
> different web services in the future. So, we'd like to setup our
> framework so that it would be least code changes/hassle on our end as
> and when we connect to the different web services. We figured WSIF
> provides us that framework, but kept seeing the samples utilize some
> "generated" code. We figure we need to come up with a solution that
> is
> not quite the DynamicInvoker extreme, but not the
> "need-to-generate-static-stubs" route either - something in the
> middle.
> Does this approach sound right?
>
> I do appreciate all the assistance/patience. :)
>
> Anuj.
>
> --- Nirmal Mukhi <[EMAIL PROTECTED]> wrote:
> > There are two kinds of ways you can go to access *a particular* web
>
> > service:
> > 1. Stub invocation:
> > Use the WSDL to generate java classes and a stub interface.
>
> > Write a small bit of code using the WSIF API to create the
> > service
> > object from the WSDL and supply it with the stub interface, then
> use
> > the
> > stub interface ot invoke the service.
> > The main advantage of this approach is that you (the
> > application)
> > use a high level view of the service (the stub interface).
> > 2. Dynamic invocation:
> > Write code to access the WSDL, build WSIF messages and
> > operations,
> > and invoke the service.
> >
> > If by "truly dynamic" you mean you want code to be able to invoke
> > *any*
> > web service, the DynamicInvoker is what you should look at.
> >
> > In terms of performance issues, DynamicInvoker will be slowly than
> > the
> > other two clients. The stub/dynamic clients will be almost
> identical
> > in
> > WSIF (stub based will be slightly slower probably), since stub
> > invocation
> > really uses a dynamic proxy mechanism (i.e. under the wraps it
> really
> > uses
> > the dynamic API, we don't actually generate a hardcoded stub class,
> > just
> > allow access via the stub interface).
> >
> > Anuj Agrawal <[EMAIL PROTECTED]>
> > Hmm.. i looked at the dynamic clients in the samples. And now i'm
> > confused (i think). I thought the dynamic clients would be truly
> > dynamic, but they ALL have references to some kind of generated
> > beans/stubs (e.g. in the localjava sample, it imports
> > localjava.client.stub.addressbook.wsiftypes.Address). Is that the
> > right approach?
> >
> > I should also explain here that i'm totally comfortable creating
> > static
> > invocation clients (using WSDL2Java tool to generate stubs etc.).
> > But
> > for our long term goals, we felt that using DII would be a better
> way
> > to go and an article on webservices.org suggested that IBM's (and
> now
> > ASF's) WSIF is a good way to go. But then on the java.sun.com's
> web
> > services tutorial, they suggest to use DII *only* if the client
> > cannot
> > use static stubs. The article also suggests that the performance
> hit
> > of using DII is not very significant - is this really the case? I
> > guess it boils down to should we or shouldn't we use DII over
> static
> > stubs? (The only article that compares the 2 approaches was the one
> > on
> > webservices.org.)
> >
> > Anuj.
> >
> > --- Nirmal Mukhi <[EMAIL PROTECTED]> wrote:
> > > The DynamicInvoker is an example of using the WSIF dynamic API to
> > > invoke
> > > any web service. If you want to write your own client that uses
> > > WSIF's
> > > dynamic API, that code would help. However since the
> DynamicInvoker
> > > code
> > > is used to invoke *any* web sevrice, it does introspection and
> > things
> > > that
> > > you would not require if you were just writing a client to access
> a
> >
> > > particular web service. You can also look at the dynamic clients
> in
> > > all
> > > the samples. There is no "recommended" way, but hopefully all
> those
> >
> > > examples will help.
> > >
> > > Anuj Agrawal <[EMAIL PROTECTED]>
> > > Ok - that clears that up. I see the DynamicInvoker class being
> > used
> > > as
> > > well. Is the code in that class the "recommended" way for us to
> > > build
> > > web service clients using dynamic invocation?
> > >
> > > --- Nirmal Mukhi <[EMAIL PROTECTED]> wrote:
> > > > WSIF allows stubless (dynamic) invocation as well as invocation
> > > > through
> > > > JAX RPC stubs. You don't have to do stub invocation if you
> don't
> > > want
> > > > to.
> > > > The sample present two alternative clients for accessing the
> same
> > > > service,
> > > > one using the dynamic API and one using a JAX RPC stub (all the
> > > > samples
> > > > follow this format).
> > > >
> > > > Anuj Agrawal <[EMAIL PROTECTED]>
> > > > I've been reading up on WSIF and it sounds great! I have a
> > > question
> > > > regarding usage.
> > > >
> > > > In the SOAP (StockQuote) sample on the ws.apache.org/wsif site,
> > why
> > > > are
> > > > (any) stubs are used in the example? I thought one of the main
> > > ideas
> > > > of the dynamic invocation was that we wouldn't need to generate
> > > > stubs.
> > > > Did i miss something here?
>
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