Sorry for late response. The system is upgraded and we don't have much notification. My suggestion is to:
1) Write an class that implements StreamSource
2) Add the webservice method on it. According to your description, the webservice is a provider instead of a client, please refer to the docs on how to implement a WS provider at OEP.
3) If needed, implement RunnableBean to start the webservice.
4) Assemble it with other stages and take this class as adapter
Thank you very for your answer.
The steps to achieve this seem to be more clear to me.
I will try and come back to you if I have any other questions.