Thanks!
It workes very well with the dynamic invocation of the webservices. I
made a few alterations of the DynamicInvocation example (to be able to
run it without the main-method) and it works like perfectly for our needs.
Regards
Roland
Tom Oinn skrev:
Roland Carlsson wrote:
Hi!
Is it possible with Axis to create stubs "on-the-fly"?
You could potentially do this if you're familiar with writing custom
classloaders - effectively you can use the WSDL2JAVA tool and then
dynamically load the byte code in the generated class files. I don't
think this is the best way to do this but it will work (the Triana
project in the UK did this to cope with web services in workflows for
example).
The correct way to do this (in my opinion anyway) is to use the WSDL
documents describing the web services directly rather than generating
stub classes - it is entirely possible to invoke arbitrary services
with complex types etc without having to go through any compilation
stage at all, by the sounds of it your requirement is something like
'discover all services, invoke service to gather stats, do analysis' -
the first part is up to you as is the analysis but you can do the
invocation on the fly.
There is a very simple dynamic invocation example in the axis code,
the most obvious question you'll have from this example is 'what about
complex types?'. In this context a complex type is anything that you
would normally have to register a custom serializer for (this is the
main thing the stub classes will do for you). If you're not compiling
and loading classes on the fly you won't be able to access these types
through java classes but that shouldn't really be a problem - soap is
all about passing XML documents around so you should be able to
intercept the xml representation of the return value and use it
directly (this is what we do in our workflow engine when calling
complex services).
Our rather more complex dynamic invocation system is visible at
http://cvs.sourceforge.net/viewcvs.py/taverna/taverna1.0/src/org/embl/ebi/escience/scuflworkers/wsdl/
with the WSDLBasedProcessor responsible for creating and configuring
an axis call object from a WSDL document and the WSDLInvocationTask
responsible for using this object to call the service. Yes, this is a
lot of code for something that should be fairly simple, no, this is
not my fault :)
HTH,
Tom
