Call Web Service method through a Proxy

Hi to all,
I am working in Java via Netbeans.
I have created a WS client through a wsdl I have.
I managed to create service object, and call operations through the port object.
But now i want to call the methods through a proxy.

I know of a solution but I dont want that as it changes System properties (System.setProperty(String, String))

Do you know of any other solutions?
THanks in advance