Yes, of course it is possible. This procedure is not specific to Eclipse. I usually use an Ant script to do the following:
1. Use wsgen to generate the WSDL file.
2. Copy the generated WSDL into the WEB-INF/wsdl directory of the web service project.
3. Add the wsdlLocation attribute to the @WebService annotation in your endpoint implementation class. The value of the wsdlLocation is to be the name of the WSDL file.