This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
The wsgen tool (http://java.sun.com/webservices/docs/2.0/jaxws/wsgen.html) is the tool in JAX-WS to generate artifacts like a WSDL from an annotated endpoint implementation class.
However, I do not know anything about the web service stack in Weblogic, so you should consult the documentation.
Note that, if you are using a JAX-WS compatible web service stack and want to use a pre-generated WSDL, you should add the wsdlLocation attribute to the @WebService annotation.