Top-Down or Bottom-Up Web Service Development

What is the best approach to web service development?

Top Down Web Service Development

The Web service wizard assists you in creating a skeleton bean from an existing WSDL document. The skeleton bean contains a set of methods that correspond to the operations described in the WSDL document. When the bean is created, each method has a trivial implementation that you replace by editing the bean.

http://help.eclipse.org/help33/index.jsp?topic=/org.eclipse.jst.ws.doc.user/concepts/cwsbtmup.html

Bottom Up Web Service

The Web Service wizard assists you in creating a new Web service, configuring it for deployment, and deploying the Web service to a server. Once your Web service is deployed, the wizard assists you in generating the client proxy and sample application to test the Web service. When you have completed testing, you can publish your Web service to a UDDI Business Registry using the Export wizard.

http://help.eclipse.org/help33/index.jsp?topic=/org.eclipse.jst.ws.doc.user/concepts/cwsbtmup.html